The Secret Formula
Could shrunken heads from the Amazon hold the key to curing cancer? One man thought so—and spent a lifetime trying to prove it.

By Steven Lance

The Atavist Magazine, No. 110

Steven Lance works as a lawyer in New York. He is originally from California.

Editor: Jonah Ogles
Designer: Ed Johnson
Copy Editor: Sean Cooper
Fact Checker: Nina Zweig
Illustrator: Simón Prades

Published in December 2020.



At noon on October 9, 1948, a group of political correspondents gathered at the Ecuadorean embassy in Washington, D.C. They were greeted by the ambassador, Augusto Dillon, a short man with slicked-back hair and a disarming smile. He led them into an elegant salon, where they were seated in chairs embroidered with gold thread. At the front of the room, the reporters noticed a six-foot-long wooden pole, an outfit made of shells and tree bark, clumps of leaves wrapped in cellophane, and eight round, leathery objects topped with what appeared to be human hair. Behind the reporters, a few balloons bobbed in the air, like leftovers from a birthday party.

Once everyone was settled, Ambassador Dillon—he went by Gus in diplomatic circles—said a few words. Then another man stood up. He wore a dark suit and rimless glasses. His name was Wilburn Ferguson, and he was the chief anesthesiologist of the San Juan de Dios Hospital, in Quito. Ferguson looked “young (40 or so),” one reporter judged, and “big, blondish.” Ferguson was an American who had lived in South America for most of the previous 17 years, studying indigenous medicine in hopes of finding new treatments for chronic diseases. Officially, he was in the United States to raise money for a new teaching hospital in Ecuador. But as one journalist noted, Ferguson had “more than a single mission in mind.”

After introducing himself, Ferguson picked up the wooden pole at the front of the room, raised it to his lips, and blew. A dart shot across the room, exploding a balloon. In the Amazon, Ferguson told the startled reporters, an indigenous hunter with a chonta blowgun like the one he held could drop a hummingbird from the highest branches of a tree. If the hunter was aiming for bigger prey, he dipped the dart in curare, a poison that could paralyze a large creature within minutes, causing death by asphyxiation.

Ferguson passed around a packet of leaves. These were the source of curare, he said, which in very small doses could control spasms. Then he distributed bark from the cinchona tree. This was used to make quinine, which revolutionized Western medicine after a Spanish missionary observed a healer use it to treat malaria. Another cellophane packet held coca leaves, used to make cocaine, one of the first local anesthetics. A tribe called the Jivaro, Ferguson said, understood the benefits of these substances long before Americans or Europeans had ever heard of them.

Finally, he turned to the round, leathery objects. “The doctor,” a reporter wrote, “began passing around human heads shrunken to baseball size.” They appeared “amazingly real,” a Canadian journalist reported. “[We] found it a grisly task, handling those long, black-haired and strikingly human, doll-like heads.” The reporters “gingerly handled them, squirmed, and passed them along.”

Ferguson thought the group might like to know how a head was shrunk. The skull and brain were removed straightaway, he explained; an incision was made from the crown to the nape of a severed head, and the face and scalp were then slipped off “like a sock.” The skull was discarded, while the husk was scraped clean, boiled in a liquid made from a mix of ingredients, and reshaped around hot sand and pebbles until it looked just as it had before death, only smaller.

“The head-shrinking rite is the most mystic and secret formula among all Jivaro religious and medical practices,” Ferguson said. The plants used in the process—the leaves and barks boiled in the liquid—had uncanny powers. Somehow, he said, they could shrink tissue “to any desired dimensions” and preserve it from decay.

At this point, Ferguson picked up what one reporter called “perhaps the most important of all his exhibits”: a glass vial containing about three ounces of head-shrinking fluid. “As far as I know,” Ferguson said, “I am the first and only white man ever to lay my hands on this.” It had taken him over a decade to find a healer who would give him a sample. To Ferguson it was more than a curiosity. The solution, he said, once it was refined and stabilized by modern science, might produce a treatment for cancer.

Someone in the audience interrupted. Could he explain that point, the one about cancer?

“It’s strictly speculation, but it’s an idea I’ve had for a long time,” Ferguson said, according to a story in The Washington Post two days later. “You see, pathologists say it’s impossible to shrink cartilaginous tissue, but headhunters have been doing it for centuries. This brew apparently holds the answer to such shrinking. Now, everyone knows cancer is unrestrained growth of tissue cells. If this fluid can shrink cartilage, perhaps it can also hold back cancer growth.”

At this point, the reporters must have expressed some skepticism. Ambassador Dillon stood up. “I don’t know about the rest of you,” he said, “but I feel like a drink.” Trays of champagne and caviar appeared. The shrunken heads were whisked away.


No one will be surprised to learn that Wilburn Ferguson never cured cancer. There have been significant advances in oncology since his press conference at the Ecuadorean embassy, from combination chemotherapy to minimally invasive surgeries to gene therapy. But shrunken heads haven’t figured into any serious efforts to treat or eliminate the disease. You won’t find Ferguson’s name on any groundbreaking medical studies.

To say that his story is one of failure, though, would be a mistake. It’s a family saga in which an unlikely theory drove a quest that spanned generations. It looped in outsiders—my own family played a minor role. For a few years in the 1960s, Ferguson and his family lived in a spare apartment behind my step-grandfather’s dental office in El Centro, California, while Ferguson looked for Hollywood millionaires to support his research. We have family photos of my stepdad, John, who was 11 years old then, wearing a feather headdress with a tail made of beetle shells which Ferguson brought back from the jungle. In his hands, he holds a pair of shrunken heads. John doesn’t look happy; in some of the images he’s practically wincing. The shells hanging down from the headdress, he explained to me, felt like they were wriggling to life every time he moved.

But John loved science as much as any kid growing up during the space race. For him, the chance to be part of “a real science project with a real scientist” was the height of happiness. He and his parents believed Ferguson’s ideas were worth pursuing. My step-grandfather, an oral surgeon, organized a committee of Ferguson supporters who gathered at the house every week, often beneath a cloud of cigarette smoke, to discuss fundraising. John borrowed his father’s camera to shoot portraits of Ferguson’s grandchildren. He made reproductions of before and after slides showing what Ferguson said was evidence that a compound he’d derived from the head-shrinking formula could reduce the size of cancerous cells. Before long, John said, Ferguson was “almost like a member of the family.” He had a friendly, straightforward way of explaining big ideas that made John think of Mr. Wizard, the popular TV scientist who taught children how to perform experiments.

Like a modern-day Don Quixote, he chased an impossible dream based more on faith than evidence.

The fundraising never materialized in any substantial way, and the Fergusons eventually left the California desert. But that wasn’t the end of the story. Ferguson kept pursuing his dream. He inspired others—friends, benefactors, unlikely strangers—to support him. More than two decades after his death, he still has followers.

The notion that he was on the brink of curing cancer is so alluring that the Ferguson faithful are willing to overlook a few things. For one, Ferguson wasn’t a doctor. What’s more, many details of his early years in the Amazon are impossible to verify; the only sources are his own writings, a recording of a lecture he gave in the late 1970s, scattered letters, his stories as other people remember them, and news articles in which he was sometimes the only person quoted. And his approach to the indigenous people his work depended on was deeply problematic. He exoticized their traditions even as he believed in the power those traditions held. He accepted the advantages that came with being white and American in parts of the world that had endured centuries of exploitation by outsiders who looked like him. At least once, by his own account, Ferguson used unproven treatments on vulnerable patients without their knowledge, a violation of basic medical ethics.

For all his faults, though, Ferguson wasn’t a snake-oil salesman or a con artist. Outlandish though some of his stories still seem, the details contained within them were consistent. The people I spoke to who knew Ferguson were struck by his sincerity. He could be stubborn and impractical, but as my stepdad recalled, Ferguson was always careful to point out that he hadn’t discovered a silver bullet, merely a promising treatment that needed more study. What he wanted most of all was a real scientific shot.

Ferguson was an outsider his whole life. Like a modern-day Don Quixote, he chased an impossible dream based more on faith than evidence. He wandered the wilderness seeking a miracle. The doctors and scientists who doubted him had every reason to. But what if they missed a bark or root of medical importance? What if Ferguson saw something they couldn’t? What if he was right?



Ferguson was born in 1905 in Shawnee, Oklahoma, but grew up farther west, in National City, California, where his parents leased a farm, raised cows, and grew fruit trees. When he was little, his mother and father often found him stuck on rooftops or buried in piles of corn; he had, as he later wrote, “an inborn urge to explore everything, everywhere.” He loved stories about adventurers and missionaries—Dr. David Livingstone, Roald Amundsen, Martin Frobisher—and felt called to follow in their footsteps.

In seventh grade, he joined the Seventh-day Adventist Church, which sent missionaries all over the world. The church was founded in 1863 in Michigan; by 1900, there were congregations as far afield as Japan. In Ferguson’s time there were already more Adventists abroad than in the United States. Adventist publications exhorted believers to carry the message of salvation across the globe. “Thousands of Indians along the banks of the Amazon and its tributaries have never heard the name of Jesus,” observed a church magazine in 1920. The same publication once asked, “Will you help answer the prayer of those faithful missionaries down there in the great Amazon? Will you help provide more workers for these benighted territories, where now thousands fall into Christless graves?”

Given his young age, Ferguson couldn’t travel abroad immediately after converting, so he got a job at a church-run hospital in California. Working nights, carrying trays through the wards for seven cents an hour, Ferguson watched patients sick with cancer and other diseases struggle and then die. “I was appalled at the almost total lack of adequate medication that we had at our disposal,” he wrote in 1973, in the self-published autobiography The Son of Fergus. The hospital was stocked with the best equipment and medicines available at the time—it was science that had fallen short. Ferguson once summoned a priest to administer last rites to several children, then an undertaker to collect their bodies. “Morphine and futile words of comfort,” he later wrote, “did not relieve the abysmal terror and unmitigated agony caused by chronic disease.”

Ferguson was impressed by how many drugs had their origins in tropical jungles—quinine, for instance. What else was out there? Perhaps every disease had a cure and the trick was merely finding it. Ferguson came up with a plan: He would befriend and live with “Primitive Medicine Men,” as he referred to them, learn about their remedies, and transform what he discovered into revolutionary medicines.

Ferguson attended Adventist colleges in California, first in Napa Valley, then in Riverside. He needed tuition money, so he convinced a friend who worked at a medical school to let him pick up overnight orderly shifts typically reserved for doctors in training. When work was slow, he asked physicians to teach him basic medical skills—how to set bones, pull teeth, diagnose anemia—that might help him win respect in communities without access to doctors. He improved his Spanish with the help of Mexican-American patients. And he corresponded with a nursing student named Ruth whom he’d met during his freshman year, when he was admitted with a fever to the hospital where she worked. (After his fever broke, he held hot water in his mouth to make it seem like he still had a temperature when Ruth came by with a thermometer—he didn’t want to leave her.) According to Ferguson, they “had a great deal in common,” and Ruth “was intensely interested” in his dream of finding medical cures in faraway jungles.

The two were married in May 1930, in a double wedding with Ferguson’s sister, in the chapel of an Adventist hospital. Ruth was 21. She had just graduated from nursing school. Wilburn, 25, was two credits short of an associate’s degree and $262.50 in debt. The couple moved to Calexico, on the border with Mexico, to teach Spanish-language Bible classes.

Ferguson’s sights were set farther south. Before the wedding, he’d applied to the Adventist General Conference for an overseas missionary posting, mentioning his future wife. (The church preferred to send married couples over single men, although wives weren’t considered employees.) Ferguson made clear where they wanted to go. “South America mission work has always been our choice,” he wrote, “and especially since we have learned to work in the Spanish language, it would be easier for us to start right in and begin working for the people than it would be if we had to learn another language.” A local Adventist elder endorsed them, writing that he believed Ferguson “would make good in a foreign field.” Another elder described Ferguson as “very good in giving treatments and helping these poor people.”

In 1931, Ferguson received a letter offering him a job as superintendent of a small Adventist mission in Sandia, Peru, “located about eight or nine thousand feet above sea level, which means you will have to have good health.” Ferguson wrote back the next day accepting the post. He added a request: He and Ruth wanted more medical training and some dentistry tools. “I had read quite a lot about Dr. Livingstone and all the other people who had accomplished things in primitive countries,” he later explained, “and most of their results came after they tended people medically.” The Adventists advanced the couple $75 and agreed to sign up Wilburn—but not Ruth—for a six-week clinical course at an Adventist hospital. (This pattern would repeat: Ruth was overlooked, though she and Wilburn did everything together.)

When Ferguson’s clinical training was complete and an Adventist doctor had pronounced his family’s health “vigorous,” he and Ruth gathered up their wedding china, cooking pots, saddles, bedding, typewriter, surgical instruments, medical supplies, rifles and shotguns, and cache of cloth diapers. By then they had a son, Eugene, whom they called Gene. They packed everything in suitcases, plywood boxes, and barrels. With the baby in tow, they made their way to the Port of Los Angeles, where a ship was waiting to take them to Peru. Soon, Ferguson was sure, he would be making discoveries that would change the world. “I guess it was a pretty wild venture,” he said decades later. “We thought it would take no more than a year or two—and, like a lot of young persons, we wanted to do big things in a hurry.”


On November 15, 1931, the ship dropped anchor in Mollendo, Peru. The family rode inland on a train that Ferguson described as snaking “along deep gorges and across bridges suspended a mile above raging rivers, through tunnels and along the crest of great cliffs.” They watched through the windows as haciendas set in fields of sugarcane went by. In Arequipa, “a beautiful city with cobble-stone streets at 7,550 feet above sea level,” the couple disembarked.

Before the Fergusons continued on to Sandia, the church wanted them to help expand and modernize its network of local schools. In early 1932, the couple reported to Adventist missionary offices in Puno, on the shores of Lake Titicaca, 12,500 feet above sea level. On market days, Ferguson found himself mesmerized by the fleet of balsa rafts that crossed the water. “It is a never-to-be-forgotten sight to see these hundreds of balsas with their sails full of wind sail out into the indescribable color of the Sunset,” he wrote. “It is difficult to decide whether the balsas fade from view over the horizon of the lake or whether oncoming night blots them from view.”

Ferguson helped build dozens of school buildings, funded partly by gold dust that he and indigenous church members panned from rivers. He traveled over llama trails on a second-hand motorcycle, a shotgun strapped to his medical bag, to assess educational needs in remote areas. He offered medical assistance to locals and pulled rotting teeth at no charge. “I never thought that there were so many bad teeth in all the whole world before,” he wrote.

By the time the Fergusons were dispatched to Sandia, about 170 miles north of Puno, in the foothills at the edge of the Amazon, rumors were circulating among Adventists that the couple had more in mind than saving souls. Ruth had told friends that she and Wilburn would stay in missionary work only until they had enough money to fund his special plans. A fellow missionary observed that “Brother Ferguson” didn’t seem “very spiritually minded.”

According to archival documents, church leaders reprimanded Ferguson. “We have not sent our missionaries to these fields just to work for gold,” one official wrote. Ferguson was indignant. “If the mission doesn’t want me here any longer, be frank about it,” he wrote. “But whatever you do, don’t allow the work to be torn down just to make me fizzle and then kick me out in disgrace.” Shocked by Ferguson’s tone, the president of the church’s South American division wondered if altitude was the problem. Perhaps, the president wrote, Ferguson “might have a change of heart and spirit and throw himself into the work and forget his little troubles” if transferred to a post closer to sea level. Others were less optimistic. “Brother Ferguson came to us with a good recommendation,” one missionary lamented, “but I feel sure that a mistake was made in selecting him.”

In early 1934, Ferguson staked a claim on an abandoned gold mine and started spending much of his time there. As his priorities crystallized, the church’s patience ran thin. “I feel that Brother Ferguson has for many months violated the very basic principles of a missionary’s life,” a church official commented in a letter. A Peruvian mission worker reported that Ferguson worked on the Sabbath, forced him to labor in the mine, and kicked him when he protested. “His work as a missionary has been a failure,” the church’s superintendent in Peru concluded. To make matters worse, he seemed to be hiding something. “Brother Ferguson,” the superintendent wrote, “has always, for many months at least, had secrets that he has not been free to reveal to anyone but his own confidential friends.”

The minutes for the 570th Meeting of the Seventh-day Adventist General Conference Committee, held on July 16, 1934, contain the following entry: “Ferguson, W.H., released from mission employ.” Church policy was to provide passage home for failed missionaries and their families. But instead of steamship tickets, Ferguson persuaded a church official to give him, as another Adventist remarked in disbelief, “a lump sum of $500 to cover the transportation of the family home and to leave him a little money in hand.” Instead of returning to America, the Fergusons pocketed the money and stayed in Peru.


For Ferguson, missionary work had served its purpose—it had brought him to South America, where he believed his destiny lay. He became even more certain when an indigenous man offered to sell him a shrunken head. “It was ugly, primitive, and spine-chilling,” Ferguson later told a reporter. He bought it anyway.

The head had blond hair and a beard, indicating that it once belonged to a man of European descent. Ferguson wrote that he felt “a profound interest” in the head and the change it had undergone. Despite its “unbelievably small size,” the face “maintained the exact proportion that previously existed between the ears, eyelids, nose, and the skin so that all facial and character lines remained exactly as they were previous to death.”

Ferguson wanted to meet the people responsible for the head, and he believed he knew who they were: a tribe called the Shuar, referred to by Westerners as the Jivaro. Among outsiders the Shuar inspired fascination and fear. Citing their “inclination to make cruel and ferocious war on their fellow creatures,” a 19th-century explorer called them “the most cruel infidels in this part of America.” Anthropologist Rafael Karsten, writing in 1923, said the Shuar were “the most warlike of all Indian tribes in South America.” A Shuar warrior’s “reputation increases,” the chief of the Smithsonian’s Bureau of American Ethnology noted, “in proportion to the number of heads he has succeeded in securing during his career.”

These descriptions were dehumanizing, to put it lightly. The Shuar did fight, but out of necessity. According to Steven Rubenstein, a modern anthropologist, “every documented instance of Shuar violence is a response to state aggression.” For centuries they resisted invasions, preserving their independence against overwhelming odds. By Ferguson’s time, as one ethnologist observed, Shuar communities had overcome “the conquering might of the Inca, the greed of the gold-hungry conquistador, and the passionate zeal of the missionary.”

Shrunken heads helped. Soldiers who fought the Shuar, according to stories Ferguson heard, might wake up one morning to find a stack of them in their camp, shriveled but still recognizable as those of fallen comrades. It was powerful propaganda, a warning to steer clear. Head shrinking was “the most effective national defense ever devised,” Ferguson wrote.

He suspected that it might be much more than that. One afternoon, while he and Ruth were inspecting the tiny features of the head he’d purchased, they made a connection. “The thought occurred to me,” Ferguson recalled, “that perhaps the active ingredients of this process could be in some way adapted to shrink, or at least check, the wild growth of cancer cells.”

By that time, as Siddhartha Mukherjee explains in his 2010 book The Emperor of All Maladies: A Biography of Cancer, scourges like smallpox and tuberculosis were yielding to medical advances. “But of all diseases,” Mukherjee writes, “cancer had refused to fall into step in this march of progress.” Cancer is out-of-control division and growth of abnormal cells that can destroy healthy tissue and spread through the body. As Americans escaped other ailments and lived longer, more of them developed the disease. By 1926, it had become the nation’s second leading cause of death.

Long stigmatized and little understood, cancer now drew widespread attention. One senator proposed a $5 million reward for “information leading to the arrest of human cancer.” Americans dreamed of finding what Fortune called a “new principle of treatment.” The Fergusons were caught up in the zeitgeist. The thought inspired by the shriveled head was simple enough: If cancer killed by growing, shrinking was a way to fight it. For the Fergusons to test their theory, they needed access to whatever the Shuar were using on their enemies’ heads.

That was easier said than done. The Shuar were hard to find; Ferguson had read that their territory was mostly in the highland jungles of eastern Ecuador and northern Peru, though their canoes were sometimes spotted on rivers southeast of there. Moreover, he and Ruth were busy. Ruth now had two children to care for; Ralph was born in 1935, after the couple’s second son, Donald, died of whooping cough. She also volunteered as a nurse, delivering babies and injecting Novocain when Wilburn pulled teeth. Still, the more Ferguson thought about the “wild idea” that the shrunken head could be vital to cancer research, “the more obsessed” he became.


The expedition started out simply enough: In 1936, Ferguson left home with a 12-year-old boy named Antonio who would help him cook and carry provisions. Antonio had worked for the family for “nearly two years,” Ferguson wrote, “and was treated as our son.” They caught a ride to a larger town, where they boarded a train to Marcapata, just east of Cusco and Peru’s most famous archaeological site, Machu Picchu. Ferguson hoped he’d be able to make contact with the Shuar in the surrounding jungle. He bought supplies and hired several indigenous men to accompany him and Antonio into the forest. One of the men claimed to speak the Shuar’s language.

The group walked for several days before they came to a cable bridge strung between two cliffs, manned by a guard who collected taxes and took down the names of everyone who crossed. This was the divide between 20th-century Peru and the Amazon. The men paid the fee and walked across. After a few days’ travel along a river, they met a group of gold miners who said they’d seen “strange Indians” going downstream in a pair of canoes the day before.

Ferguson’s group made camp, and while most of the men set to work building a canoe, cutting down a tree and hollowing out the trunk with adzes, Ferguson went scouting. He brought the man who said he spoke Shuar. Antonio “begged very hard to go with me,” Ferguson wrote afterward, “but I felt that if an encounter with the Jivaros became possible I should be alone with the interpreter. I didn’t want him hurt in case trouble developed.”

For two days, Ferguson and the interpreter hacked their way through dense jungle with machetes but encountered no one. On the third day, they came upon another group of miners who said they’d seen canoes on the river, but they didn’t know where the people in them had come from or where they’d gone. Ferguson and the interpreter returned to camp, only to find it empty. “There was not a soul,” Ferguson wrote. Nothing was missing or out of place—“the dishes [were] clean, pots and pans were where they should be; ready for the next meal.” The men’s ponchos had been neatly folded. Their food was tied up out of reach of wild animals. The newly completed canoe sat moored to a tree.

The thought inspired by the shriveled head was simple enough: If cancer killed by growing, shrinking was a way to fight it.

Ferguson wondered if the group had hiked somewhere. Perhaps they’d become bored while waiting and decided to go fishing. Hours passed. Ferguson began to worry about young Antonio. Night fell with no sign of the group. Another day passed, then another night. “Clearly,” Ferguson wrote, “something was very wrong.”

He and the interpreter made their way to a trading post a few miles away. No one had seen the missing men. They returned to the cable bridge and asked the guard if anyone had crossed back over. No one had. “There were tremendous cliffs here and it was extremely difficult, if not impossible to go around this check point,” Ferguson wrote. “My men clearly had not been there.”

“Dead or alive,” he concluded, “they were still in the jungle somewhere.”

Ferguson went to the regional capital and told the chief of police what had happened. The chief already knew—he’d received a telegram from mounted officers in the jungle. Officially, Ferguson learned, “the Government was making out the report that my men had become impatient at my absence and had tried to swim the river where all of them had drowned.” But that may have been a cover story. “Unofficially,” the police chief told Ferguson, “the evidence indicated that they were ambushed by the Jivaros.”

Decades later, Ferguson recalled the chief’s blunt assessment: “The Jivaros killed all your men, cut their heads off, and dumped their bodies in the river.” Ferguson was told to flee. Several men and a child—Antonio—had died; their relatives would blame him.

Ferguson took a train to the coast to meet Ruth and their sons. They boarded a ship that carried them to Panama, and then another headed to California. Some years later, when Ferguson told a Peruvian general about his attempt to track down the Shuar, the man was horrified. “You’d better thank God you never found them,” he said. But Ferguson wasn’t done looking.



While Ruth and the boys stayed in Los Angeles, Wilburn returned to Peru, where he scoured museums, libraries, and pre-Inca graves in search of lost medical secrets. In 1939, he caught a “a little wood-burning steamer” that went down the Amazon, traversing Brazil. The trip took almost two months. Ferguson discussed history and religion with an old Jesuit priest on the boat, bought dried fish in river towns, and photographed men standing up in canoes to shoot long arrows. When the steamer reached the Atlantic coast, Ferguson convinced the captain of a Norwegian freighter heading to America to take him on as a crew member. He was back in California in time to hear the news about Pearl Harbor.

As World War II raged, the Fergusons ran a pair of small nursing homes, first in Glendale, California, and then in Idaho. (Ferguson had become a registered nurse after his first excursion to South America.) In 1943, Ruth gave birth to a daughter, Eileen Patricia, whom they called by her middle name. According to his autobiography, Ferguson commuted by overnight bus to Chicago to study anesthesiology with Dr. Ben Morgan, a pioneer in the field, but he never completed a degree.

By early 1945, Ferguson was desperate to get back to the jungle. He went to Washington, D.C., to obtain travel documents. While there he somehow met Ecuador’s ambassador to the United States. His name was Galo Plaza, and he was practically Ecuadoran royalty. Plaza’s mother, Avelina Lasso de la Vega y Ascazúbi, belonged to one of her country’s oldest landowning families. His father, General Leónidas Plaza Gutiérrez, had twice been the country’s president. Plaza was born between those stints, while his parents were living in Greenwich Village and his father was a diplomat to the United States.

Plaza was not yet 40 when Ferguson met him. He was rich and handsome, a cattle rancher who’d played football as an undergraduate at Berkeley and later studied at Georgetown. He’d already been the mayor of Quito and Ecuador’s minister of national defense. The two men hit it off, and Plaza offered him a job in Ecuador’s new public hospital system. In July 1945, Ferguson went to Quito. He planned to get settled and then send for his family. At the time, Ecuador was one of the western hemisphere’s poorest countries, but the capital’s rich neighborhoods boasted tree-lined avenues and Spanish-style mansions. Thanks to Plaza, Ferguson was welcomed by Quito’s elite.

After Ruth and the kids arrived, the Fergusons moved into a house across the street from Plaza’s family. Ruth began working as the head nurse for the public hospital system. Meanwhile, despite the fact that he wasn’t a doctor, Wilburn treated patients in Quito and flew to Guayaquil and Cuenca to see others.

Plaza soon ran for president. While conservatives and socialists attacked one another, he positioned himself as an independent and won. The New York Times, reminding readers of his Manhattan birthplace, called Plaza “a local boy who made good.” Once in office, Plaza named Ferguson “senior consulting anesthetist” to the public health service and the armed forces. Plaza gave Ferguson a pass to ride military planes into Shuar territory. And he persuaded the faculty at the University of Cuenca to hire Ferguson as a professor of anesthesiology, despite their misgivings when they learned that he didn’t have a medical degree. The university’s solution, according to Ferguson, was to award him an honorary doctorate.

As Ferguson once joked, “the combined salaries of all these posts would hardly be considered cigarette money in the States.” But in Ecuador it was more than enough. On weekends, Ferguson began taking camping trips with a doctor’s bag, setting up his tent in areas where he believed the Shuar lived. “When the people became curious,” he wrote in The Son of Fergus, “I told them that I was merely resting, but if there were any sick or that needed badly decayed teeth extracted, I would be glad to help them in exchange for a little fruit or vegetables I could cook for my meals.” He set fractures, pulled teeth, and supplied patients them with modern drugs or home remedies of his own invention. “I was always careful to treat them the best I knew,” he wrote, “and then told them to go back to their medicine man for further treatment.”

On one trip, Ferguson heard that a Shuar healer wanted to see him. The man was ill. Through an interpreter, the man described his symptoms, and Ferguson diagnosed a kidney infection. He gave the man medicine and checked on him each time he returned to the jungle. Eventually, the man asked what he owed. There was only one way to compensate him, Ferguson replied: “My fee for saving your life is simply a pot of the complete plant extract” used to make shrunken heads.

The healer protested. Such secrets weren’t shared with outsiders. However, as Ferguson told a group of supporters many years later, “The medicine men, and anybody in that area, if they think somebody actually saved their life, they’re duty bound to come up with payment.”

What happened next, if true, was a scene straight from the adventure stories Ferguson read as a child: One night, there was a knock on the front door of his family’s house in Quito. According to Ferguson’s autobiography, he put on a bathrobe and went outside, thinking he might find a runner with news of an emergency at a hospital. No one was there. Ferguson was about to go back inside when he spotted something on the ground—“a typical Jivaro gallon clay pot with a leaf cover, tightly tied to the top with a jungle vine.”

He woke Ruth. Together, they opened the pot and found that it contained a dark liquid. They poured the fluid into a Pyrex jar to examine it. “There were little globules of fat and human hair,” Ferguson later recalled, “so I had the real thing, I knew that.”


Wilburn and Ruth had no idea what was in the head-shrinking fluid, so they decided to test it for toxicity. They injected samples into guinea pigs and soaked human tissue in the liquid. (Ferguson wrote about bringing the latter home from a Quito hospital.) Even the largest dose wasn’t fatal to the guinea pigs. The human tissue shrank but, according to Ferguson, showed no signs of damage or decay. When he looked at it through a microscope, he saw intact cell membranes and nuclei.

Next, Ferguson took some of the fluid to a hospital “to run a few private tests.” He doubted it was poisonous, but his real concern was whether it could be used to treat cancer. He mixed the fluid with lanolin and made an ointment, then chose a few patients in the cancer ward whose tumors broke their skin—in his autobiography, Ferguson wrote that the growths resembled heads of cauliflower. While changing the patients’ bandages, he rubbed the ointment on the tumors. He didn’t tell them what he was doing.

Over several days, he watched for changes. Soon, according to Ferguson, lesions “began to disintegrate,” and diseased skin seemed to “slough off of the tumor[s], leaving a clean base that appeared to be normal tissue.” Ferguson continued: “Even more interesting, spontaneous tiny islands of new tissue” developed where the malignancy had been. These would spread “until the entire area was covered with new skin.”

There is no way to corroborate any of this. It’s possible that it happened, but so is Ferguson imagining the results he wanted to see or inventing a narrative of success to advance his agenda. Whatever the case, he was convinced he was onto something. “Ruth’s and my wild hunch had now developed into a definite potential therapeutic active drug principal for the possible control of cancer,” he recalled.

As the pot left on his doorstep ran dry, Ferguson flew into the jungle as often as possible, looking for more Shuar healers. He also contacted powerful acquaintances in the capital to obtain funding for his research. In 1948, the British Council in Quito helped him organize a lecture tour at medical schools in England and Scotland. That October, with Plaza’s blessing, Ferguson traveled to the United States to campaign for donations for a new teaching hospital—and to find sponsors for his work. That’s how he wound up at the Ecuadorean embassy, popping a balloon with a blow dart and passing around human heads.

The reporters who witnessed Ferguson’s demonstration didn’t know what to make of it. “It was the weirdest press conference I’ve covered in many a day,” one wrote, “and I’ve covered some zanies.” Journalists joked about “big heads” that could use some shrinking. The best doctors in the world hadn’t cracked cancer’s code. It seemed unlikely that this dreamer would.

But one reporter, Milt Dean Hill, who was friendly with Plaza, wrote letters of introduction to prominent New Yorkers who might be able to help. According to Ferguson, he and Dillon, the Ecuadoran ambassador, met with Dwight D. Eisenhower, recently named president of Columbia University. Ferguson also tried to meet with Nelson Rockefeller, grandson of John D. Rockefeller and another friend of Plaza’s, but he was only able to talk to two employees. No money materialized from either encounter. (Rockefeller later commented that his staff’s appraisals of Ferguson were “not very enthusiastic.” One of them had concluded, “This is strictly between us, but he impressed me as being far from a balanced individual.”)

After New York, Ferguson flew to Texas, where the response was more encouraging. He presented a general hypothesis—that there were undiscovered plant remedies for various ailments waiting for the right people to come along and find them. Professors at the University of Texas at Austin found the notion intriguing. After an aide to Governor Beauford Jester suggested that Ferguson’s proposal held both scientific and commercial promise, the governor wrote an introductory letter for Ferguson indicating that he hoped the project would “bring worldwide recognition and distinction to Texas.”

Jester’s staff arranged a press conference in the state capitol on November 4, 1948. Ferguson displayed his shrunken heads, explained his cancer theory, and held up his precious vial of Shuar fluid. Theophilus S. Painter, the president of UT, and Henry Burlage, the dean of the university’s pharmacy school, told reporters that they looked forward to working with him. Another wave of stories about Ferguson rippled across the middle pages of America’s newspapers.

Buoyed by the reception, Ferguson proposed a research center at UT, to be named after Pedro de la Gasca, a 16th-century Spanish bishop who once governed Peru. The center would be a joint venture between UT’s colleges of pharmacy and medicine, with its purpose “to collect, classify, purify, test, and clinically prove the value of new drugs from natural sources.” Ferguson wanted to be the director. He asked for 10 percent of the royalties from any drugs the center developed, an $8,000 salary, a $31,000 budget for general expenses and travel, and a one-time allotment of $11,000 for camping equipment, cameras, medical supplies, a boat, and a “four-wheel drive Dodge Power Wagon equipped with refrigeration, generator, drying equipment and all other … equipment necessary to get to difficult places and collect unstable drugs … and plants with high moisture content.”

Burlage’s pharmacy school was on board with the idea, but Chauncey Leake, the executive vice president of UT’s medical school, shot it down. Ferguson had been signing letters and telegrams “Doctor Wilburn Ferguson” and “Wilburn Ferguson, M.D.,” despite having neither a medical degree nor a doctorate. On top of that, Leake said, Ferguson’s chances of finding an undiscovered miracle drug were basically zero. Pharmaceutical companies had scoured the world’s jungles. If there was a plant that cured cancer, it would have been found already. “The well-known principle of diminishing returns,” Leake said, “has been cumulatively operative in these efforts for the past century.”

Burlage and Ferguson persisted with the idea of opening the center, but other people’s enthusiasm dwindled. Whenever pharmacy professors followed up with Painter about the proposal, the university president kept repeating, “Where will we find the money?”

They never did. Governor Jester, who had encouraged Ferguson, died in office, and the pharmacy school couldn’t afford to create the foundation alone. “There is very little of an encouraging nature to report to you,” a professor wrote to Ferguson. “All I can say is that you have my best wishes and that some form of help and interest will ultimately reward your perseverance and unstinting efforts.”

Ferguson returned to Ecuador empty-handed.


When Ferguson heard about the deadly outbreak, he was visiting a Shuar group he knew as the Kenguimi just outside Sucúa, a small village in the jungle with a military airstrip. It was early 1949. “Word came of a wave of fever that spread like wild fire,” he wrote in his autobiography. A warning from the country’s public health service confirmed his fears: It was typhoid. “I had always had a particular phobia against typhoid fever,” Ferguson recalled. As a boy, he’d lost two cousins to the disease.

He asked Ruth to catch a plane to Sucúa to help him. They built shelters out of palm leaves for sick Kenguimi, put buckets of disinfectant outside each one, and instructed people who touched the patients to wash their hands in them. “We dug holes where everything used by the sick Jivaro was dumped,” Ferguson wrote. “Each morning kerosene was poured over everything in the holes and set on fire.” They treated the patients with Aureomycin, an antibiotic developed a few years before.

One day a Shuar man brought his sick daughter to the makeshift hospital. According to Ferguson, the man arrived carrying a spear with a tip that had been dipped in poison. “With spear point at my back,” Ferguson later said, “I administered the drug and waited. The Jivaro girl responded to the treatment, and her father responded by introducing himself as Tangamasha, chief medicine man of the Kenguimis.”

Ferguson and Tangamasha became friends. They were about the same age, they were both fathers, and they had dedicated their lives to healing the sick. Ferguson took Tangamasha’s expertise seriously, and Tangamasha returned the courtesy. They exchanged information about remedies and methods—Tangamasha showed Ferguson which plants might help his son Ralph’s asthma, while Ferguson showed Tangamasha how to use a stethoscope and make casts for broken bones.

Tangamasha was Ferguson’s best hope for finding out how to make the head-shrinking liquid. As he wrote in The Son of Fergus, his new friend “was the key to the project.” But when Ferguson made his request, Tangamasha “was quite horrified.” He explained that his tribe’s council of elders and medicine men had to approve any new apprentice of its healing methods. It was a request Tangamasha was not eager to make. What if Shuar medicine could help the wider world, Ferguson asked. Tangamasha “pleaded, cajoled, and even threatened me,” Ferguson recalled, “but in the end, agreed to ask the council for a decision.”

About two weeks later, the Kenguimi elders and medicine men informed him that his petition was conditionally approved. According to Ferguson, they’d consulted Wakani, the Shuar god of healing, and decided that Ferguson’s medical knowledge made him a worthy candidate for the healing apprenticeship. But there was another entity they hadn’t heard from yet. In Ferguson’s understanding, it was a god of evil spirits named Pangi, who lived in a volcano called Sangay. The mountain, which had been in active eruption since 1934, was sacred to the tribe. According to his autobiography, Ferguson and the Kenguimi elders and healers trekked toward the cone-shaped volcano floating high above the jungle.

At the base of the peak they built an altar and sacrificed a pig. As Ferguson watched, Tangamasha bent down to collect the pig’s blood in a clay jar. “He dipped his finger in the blood and spread it onto my shin,” Ferguson wrote. “I then dipped my finger in the blood and spread it on his shin.” The other men repeated the gesture. Then they roasted the pig and served it “with all the vegetables and fruits of their plantations, in the special feast this ceremony required.” The Shuar watched the volcano for omens. When the pig’s throat was cut, Ferguson recalled, “Sangay quit smoking for quite a little while, and then gave three great big puffs of smoke, threw out tons of molten rock and stuff, and they said, ‘Well, that’s it. That’s approved.’” (Ferguson appears to have made some errors in his account. For instance, according to anthropologist H. Clark Barrett, pangi is the Shuar word for “anaconda.” Also, the Shuar don’t worship a god called Wakani, but they do use the word wakan, which translates as “soul” or “spirit” and is associated with ayahuasca.)

Only one test remained: Ferguson had to shrink a head. Traditionally, this would require killing an enemy, but the elders agreed to let Ferguson kill a monkey instead. Tangamasha supervised the process of removing the scalp and face and boiling it in the secret solution. When the elders inspected Ferguson’s work, they approved. They gave him several batches of the precious fluid and described the steps that went into making it. “I learned that there was a variation in the number of plants used,” Ferguson later wrote, “that ranged from 26 to 34.” Tangamasha’s personal recipe called for 30.

Each ingredient had to be extracted from a different vine, flower, leaf, or bark. The ayahuasca vine, which the Shuar believed allowed them to see the future and learn hidden truths, went into the mixture. So did cinchona, the source of quinine, and rabo de mono (monkey’s tail), a vine with fibrous roots used by Shuar healers to treat dysentery. When Tangamasha explained each plant’s properties, Ferguson “was awed at the unbelievable enormity” of what was in the fluid. The recipe involved the whole Shuar medicine cabinet, “the ultra-secret pharmacopeia of … ancient medical knowledge.”

But were all the ingredients really necessary to shrink a head? Back home, with supplies he’d gathered in the jungle, Ferguson removed plants from the formula one by one, verifying with each omission that the brew could still reduce an animal’s head. “If the resulting shrinkage factor remained the same, [the ingredients] were permanently left out of the projected chemo-therapeutic compound,” he wrote. “If the shrinkage factor was lessened, that plant was restored to the formula.” Ferguson whittled the mixture down to eight plants, amassing a collection of shrunken monkey, sloth, and cow heads in the process.

Ferguson was eager to test the compound on cancer patients. Plaza’s government arranged a “preliminary clinical test” at the University of Cuenca’s hospital. Ferguson hadn’t settled on a reduced formula yet, so he figured he’d use batches of solution that the Kenguimi had given him. “I was ready,” he wrote, “to proceed with advanced research.”



The Cuenca doctors selected seven terminal patients with tumors that they judged were inoperable. All seven were impoverished, and the six mentioned by name in Ferguson’s reports were women. The plan was to treat the tumors topically. In the first few days, Ferguson believed that he saw progress; just like in his unsanctioned experiments in Quito, the tumors seemed to shrink, and the skin around them seemed to be healing. The fluid’s “powerful killing power,” Ferguson noted, appeared “to affect only malignant growth without the least damage to normal tissue or even the new growing normal cells.”

When the mixture the Kenguimi had given him ran out, Ferguson prepared a new solution from the eight plants he believed caused tissue to shrink. But the effect wasn’t the same. His patients’ tumors seemed to grow back. Years later, Ferguson would describe this as “the most serious crisis of our entire research project.” He left the patients in Ruth’s care and took a train to Quito, where he caught an air force plane to Sucúa. He told Tangamasha what had happened and asked him to walk through the process of preparing the fluid again.

According to Ferguson, Tangamasha immediately identified the issue: The mixture the Kenguimi elders gave Ferguson had been used to shrink a number of heads. Ferguson’s mixture couldn’t compete. The missing ingredient, he reasoned, must have been some kind of “glandular, hormonal, or enzymic substances from the fresh head.” Ferguson decided that he’d have to “temper” each new batch before using it. Back in Cuenca, he bought a calf’s head from a butcher and soaked it in the fluid. Once the head shrank, he brought the solution to the hospital and resumed his experiments.

Ferguson’s writings don’t say whether he explained the treatment to the patients. If he felt ethically conflicted, he never mentioned it. He was focused on whether his project would succeed. “No one ever knew the sheer agony Ruth and I went through during the week of crisis,” he wrote. “But somehow, out of all this mess, the solution I made, tempered by shrinking a calf head, works even better.” Better, that is, than the original solution.

Only three of the seven patients stayed for the entire course of treatment; the others left for home as soon as they began to feel better. According to Ferguson, the three who stayed recovered completely. After 100 days of treatment, he wrote, Tránsito López Orellano—a middle-aged cook who entered the study with epithelioma of the cervix and uterus, or growths on the lining of those organs—had no sign of cancer. The doctors performed a hysterectomy and declared her “completely free of her former cancer symptoms.” Four weeks after her surgery, on October 31, 1949, she was discharged. Jesus Vázquez Córdova, a 70-year-old housewife who’d been admitted with a cancerous growth on her nose and cheek, also went home symptom-free, Ferguson recorded, after the doctors operated on her shrunken tumor. Josefa Carpi Cabrera’s case left the deepest impression on Ferguson: The tumor on her nose disappeared without surgery. On November 16, the hospital staff decided she could go home, too. “There was no doubt whatsoever,” Ferguson wrote, “that our own crude, eight-plant research drug compound effectively destroyed malignant tumor[s] in human patients.”

He realized, however, that the Cuenca experiments wouldn’t stand up to peer review. He wanted to run tests with more scientific legitimacy. Ferguson wrote to J.E.M. Carvell, the British ambassador to Ecuador, explaining that his “Scottish descent and a longstanding desire to take the British Medical Examinations” made him “especially interested” in working in the United Kingdom. “My most urgent need now,” Ferguson wrote, “is a connection with the best Scientists available to advise me in the Laboratory and later in a completely controlled series of clinical trials, that will leave no doubt whether or not I have something worthwhile in the treatment of Cancer.” He attached a report summarizing the Cuenca trials and enclosed before and after photographs, diagrams, and authenticated copies of his patients’ medical records.

If anyone in the UK was interested, Ferguson wrote, “I will furnish all the plant material required both for laboratory and clinical work.” He would cover the costs of collecting and shipping the plants and pay for his own travel. “However,” he added, “due to the many years of costly preliminary research which has already been done, all at my own expense, it will be necessary for as liberal a grant as possible to enable me to maintain my family with me in the United Kingdom.”

Carvell reviewed Ferguson’s report and, satisfied with what he read, forwarded it to the Foreign Office in London, which sent it to a government committee on medical research. The committee was skeptical. For one thing, it said, the treatments were too recent to be described as cures. “Moreover,” one doctor wrote, “ulcerated growths, such as Mr. Ferguson describes, are usually associated with a secondary infection.” There were probably natural antiseptics in the plants he was using, which “would be quite likely to cause even striking temporary improvement in the appearance of superficial cancers without, however, necessarily influencing in any way the ultimate course of the growth.”

In other words, the committee thought Ferguson was looking at infections caused by cancer and seeing tumors. When the infections improved, he thought he was curing the disease. “In the view of the Council and their advisers,” the British experts concluded, “no useful purpose would be served at present by Mr. Ferguson’s being brought to this country, as he proposes.”


It took several months for Ferguson to find a powerful new believer. In August 1950, he heard that there was interest in California, where he’d sent samples of his fluid. Paul Kotin, a pathologist at Los Angeles County General Hospital and a professor at the University of Southern California, tested the mixture on several strains of disease-causing bacteria. In laboratory conditions, Kotin wrote, the head-shrinking solution killed “pneumococcus, the organism which causes lobar pneumonia, the beta strep, the organism responsible for diseases like strep throat, childhood fever and the like, the staphylococcus, the organism which causes boils and abscesses, and certain organisms producing severe dysentery and diarrhea.” Kotin and his colleagues wanted more samples—and to meet Ferguson in person.

Ferguson asked for a fellowship. He wouldn’t need a paycheck, he said, just access to lab facilities and animals for testing. Kotin suggested that Ferguson join “the cancer research section at both the hospital and university here” for one year; he would “be provided with adequate space and such animals and equipment as might be necessary to further your investigations.” After that, Kotin wrote, the hospital’s doctors would help him apply for longer-term funding.

Ferguson and his family left Ecuador and moved to an apartment in Los Angeles, across the street from the hospital. Ruth got a nursing job to support the family. Gene went off to college. Ralph, a teenager, worked in his father’s laboratory on weekends and holidays. Patricia was young enough to need supervision, so after school she stayed in the lab with her father, often late into the night. To keep her entertained, Wilburn bought Patricia a miniature chemistry set.

The Los Angeles doctors began studying the exotic mixture they called “head-shrinking compound 101-A,” which Ferguson had transported in substantial quantities from Ecuador. The solution was distilled into 50 fractions—groups of chemicals separated from the overall extract by boiling them out bit by bit, in an effort to isolate active ingredients—and given code names like “101-A4/A” and “101-A4/C3.” But the doctors could only learn so much, because Ferguson was secretive. He wouldn’t tell them the names of the plants he used or how he’d processed them to prepare his solution.

On weekends, Ferguson raised money. Thanks to a wealthy cotton farmer who sent regular checks, he could afford to hire graduate and postgraduate students to assist him with the research. They spent long hours at the hospital, supervised by Kotin and his staff, who were impressed with many of the results. “The range of susceptible organisms to solution 101-A in the laboratory is wider than that of any other antibiotic or other form of bacteria-killing medication available today,” Kotin wrote. Ian MacDonald, a professor of surgery who reviewed Ferguson’s experiments, said that the solution showed “antibiotic activities which seem to exceed greatly those of such agents as penicillin.” Ferguson later wrote that the doctors were also “intensely interested in my empirical concept regarding the shrinkage factor of the crude plant extract as a potential tumor reducing therapeutic.”

Some fractions, Ferguson wrote, eliminated tumors in mice and left the creatures unharmed. Other fractions had the same results with leukemia, he claimed. “As in most scientific research, more questions were discovered than positive answers found,” he wrote, “but the research project was enormously advanced during the year’s work.”

The hospital applied for a grant from the National Cancer Institute to help Ferguson continue his work. As the chair of the hospital’s tumor board wrote, the doctors and USC professors had “confidence” in the research and were “inclined to believe that this project has great potential possibilities.” But the grant application was rejected. According to Ferguson, the reason offered by the NCI was that “the concept of the research did not coincide with the current scientific cancer knowledge.”

Without money to continue his work in California, Ferguson returned to Ecuador. He enlisted Tangamasha to collect more plants. In a Guayaquil hospital, he treated patients suffering from terminal cancer using IV drips, creams, and injections of the fractions he’d developed in Los Angeles. Local newspapers began trumpeting Ferguson’s research. The Associated Press picked up the story, wiring it to newsrooms across America. A cure for cancer, one article suggested, might be only “four or five years” away.

Thanks to the media coverage, the pendulum of Ferguson’s luck was about to swing yet again.


Drew Pearson was one of America’s most prominent journalists. The radio host and newspaper columnist was known for a trademark blend of news, gossip, and something he called “predictions of things to come”—all informed by supposedly well-placed, confidential sources. His column, the Washington Merry-Go-Round, had 50 million daily readers. His radio shows were piped into living rooms nationwide. His speaking voice was high, fast, and insistent. He could be combative, especially when he thought powerful people were acting hypocritically. Joseph McCarthy once jumped Pearson in a cloakroom after the host made a remark he didn’t like. (A young Richard Nixon had to break them up.) Pearson was also an old friend of Galo Plaza’s—the two men had bred cattle together in the 1940s.

On October 5, 1952, Pearson introduced Ferguson to his widest audience yet. It started that Sunday morning, with Pearson’s newspaper column. “For several years an American doctor has been living in Ecuador,” Pearson wrote, “experimenting with a fantastic, secret solution which may prove the answer to cancer. The doctor is Wilburn Ferguson.” He continued: “The solution he is working on is that used by the Jibaro Indians to shrink human heads. Dr. Ferguson emphasizes that he has not found a cure for cancer, that he has only found a ‘promising treatment.’ Nevertheless his clinical records have shown some miraculous recoveries.”

In his column and on his radio show that same week, Pearson cast Ferguson’s theory as the insight of a genius. He invited his audience to picture Ruth and Wilburn working by night in a foreign land, “grinding herbs and preparing their solutions for the next day’s work.” He recounted Ferguson’s time in Los Angeles and urged the public to open their pocketbooks. “Dr. Ferguson unquestionably could have made a fortune with his new cancer formula,” Pearson wrote. Instead, he was broke.

After the broadcast, people wrote letters to their local radio stations, hoping Pearson could put them in touch with Ferguson. Some sent money. Others sent advice. Mostly, though, people wanted him to treat their loved ones.

“I am willing to go to any length to get Mrs. Daugherty to him if at all possible,” one I.J. Daugherty wrote from Ohio. “She is able to travel at this time, as the cancer is in the early stage.”

“We love our Dad, Mr. Pearson,” Louis Bence wrote from Illinois, “and would try and do anything to try and get him well.”

“We want to give her every possible chance,” wrote Jack Epstein, of Pennsylvania, referring to his wife’s 31-year-old sister, “so won’t you please let us hear from you as soon as possible?”

They wanted someone to have the cure—they needed someone to have it.

Pearson’s portrayal of Ferguson—an optimist in exile, poised to return home with a miracle drug if only he had more support—resonated with a vulnerable subset of postwar Americans. Who could blame them? Medicine had never felt more modern, yet their loved ones were dying of a disease known to afflict humans since antiquity. They wanted someone to have the cure—they needed someone to have it. Letters and phone calls flooded Los Angeles County General Hospital, too. “Since the Drew Pearson talk, the situation has gotten out of hand,” a doctor there complained to a colleague, “and we are being bothered by inquiries from all over the United States.”

John and Bernice Ptak, a working-class couple from Wilmington, Delaware, went further than anyone else. Their five-year-old son, Johnny, had been sick for months. Initially, their physician diagnosed him with rheumatic fever, then polio. After an operation in Philadelphia, doctors identified Johnny’s condition as neuroblastoma—cancer of the nerves. On October 1, just before the Ptaks heard Pearson’s show, Johnny was given three weeks to live. The cancer had spread to his lymph nodes and pelvis.

In Guayaquil, on October 15, Ferguson received an urgent telegram, transmitted by radio from a Pan American flight. The message asked him to meet the plane at the airport with an ambulance. The Ptaks had emptied their savings account to bring their son to Ferguson. When the plane landed in Guayaquil, Johnny was unconscious. Ferguson and an Ecuadoran doctor checked him into the hospital and administered the head-shrinking fluid through an IV drip. On the second day, according to Ferguson, Johnny woke up briefly and recognized his father. Gradually, over several days, he seemed to improve. Ferguson and the doctors removed the IV and twice a day gave Johnny drinking water with the Shuar solution mixed in. He seemed to be responding.

Three weeks into the treatment, Ferguson wrote, “The patient was considerably improved and has a good appetite.” By November, Johnny was sitting up, talking, and playing with toys. Soon he was well enough for his parents to take him on day trips. According to Ferguson, Johnny insisted on climbing trees and playing with other children in a park across the street from the hospital. His parents were thrilled.

But something wasn’t right. Johnny’s pulse was too high, and he couldn’t sit still. His heartbeat was irregular, Ferguson observed, “and was impossible to count when he played hard.” Ferguson wondered if something in the fluid had “acted too fast for this particular patient’s cardiac condition.”

On Tuesday, December 9, 1952, Ferguson wrote a brief note: “Patient collapsed while playing.” The next day, Johnny died.

Ferguson claimed that a postmortem examination showed Johnny’s tumors had shrunk to “approximately 1/5 of their pre-treated size.” True or not, Johnny’s parents had seen his mood, appetite, and energy improve. Exactly two months after arriving in Ecuador, the Ptaks returned to Delaware with their son’s body. The press was waiting for them. “Christmas Hopes Die with Boy of 5,” one headline read. Mr. Ptak said they had no regrets about the trip to Ecuador. “We knew it was a desperate mission,” he said. “Our hopes weren’t high. We knew it was only a long shot.” Of his son, Ptak said, “He enjoyed his last days, and he passed away happily.” As for Ferguson’s compound, “If it doesn’t cure, it does relieve the pain.”

“I still have faith in Dr. Ferguson,” Ptak told a reporter. “I think we got Johnny there too late. If we had heard about him sooner, he might have saved our boy.”


Ferguson was getting more attention than ever, and not just from the media. “About a month ago news of my work leaked out,” he wrote to a doctor in Los Angeles in the fall of 1952, “and the representatives of Merck, Abbott, and a couple other drug firms called on me. This was followed up by a week’s visit from the Vice President of Merck.” Merck’s associate director of therapeutic research “took 25 liters of concentrate solution back with him for an all out evaluation.”

In late November, the U.S. government sent an NCI pathologist to Ecuador to examine Ferguson’s patients and collect biopsies. According to the pathologist’s report, Ferguson showed him “rather convincing” evidence that the head-shrinking solution reduced cancerous tumors in humans. “All of his treated patients still have cancer,” the pathologist added. But the ones he saw displayed remarkable improvement.

Not so long before, the NCI had rejected Ferguson’s grant application to continue his research in Los Angeles. What had changed? Certainly the press attention might have affected perception of Ferguson’s project, but oncology was also evolving. For decades, surgery and radiation were the only forms of cancer treatment, but recently a new approach had emerged. One proponent described it as “penicillin for cancer.” Others used terms like “selective poison.” The one that stuck was chemotherapy.

By 1952, as Mukherjee recounts in The Emperor of All Maladies, experiments at Yale and Boston Children’s Hospital had established the basic idea behind chemotherapy: Find a toxic chemical that kills cancer cells faster than it does healthy cells, and if a patient can survive the dose it takes to wipe out the disease, a cure is possible—at least in theory. The truly lifesaving breakthroughs in chemotherapy were still years away. For all their promise, early trials typically bought patients only a few months before the disease came raging back. Still, evidence that chemicals could stop tumor growth and prolong life shook the medical world.

If tumors could be reduced by compounds derived from mustard gas and periwinkles—early sources for chemotherapy regimens—why not a mixture made from jungle plants? Shortly after Johnny Ptak died, Memorial Sloan Kettering Cancer Center brought Ferguson to New York City for a meeting. The research staff arranged a deal with Merck to evaluate Ferguson’s formula together. The idea, as Ferguson described it, was that he would provide the solution, while Sloan Kettering would handle the animal testing on Merck’s behalf and, if warranted, set up clinical trials with human patients.

Ferguson recalled signing a contract with Merck on February 6, 1953. A Merck representative told me that its archivists couldn’t find any record of Ferguson—possibly because the company didn’t retain contracts, meeting minutes, or correspondence from the people and departments he interacted with. Letters in Nelson Rockefeller’s papers, however, corroborate the broad strokes of Ferguson’s deal with Merck and Sloan Kettering, to which the Rockefeller family has long had strong philanthropic ties—it even donated the land where the hospital is located.

The cancer center’s scientists began testing the head-shrinking mixture on tumors. “The first survey tests,” Ferguson wrote, “covering the entire spectrum of 20 animal tumors … showed our extract active against sixteen.” But when the team repeated the experiments, “the results were not borne out.” Perhaps, Ferguson suggested, the solution had become contaminated between tests. He telegrammed Ruth in Ecuador and asked her to send six liters of extract to New York by airmail.

But Merck wanted more than six liters. According to Ferguson, the contract called for him to produce 400 gallons of the solution. He offered to make sufficient quantities from dried plants he’d put in storage in Los Angeles, “in case of revolutions” or other catastrophes that might deny him access to the jungle. In the past he’d used only fresh ingredients, so he told Merck that he wasn’t sure the stored plant material would work. Still, the company advanced him $2,000, and Ferguson flew to California. When he returned to the East Coast with the dried plants, he prepared his formula under Merck’s supervision.

Soon after, Merck’s scientists announced that they were having trouble getting a consistent, stable assay from the new solution—that is, they couldn’t determine or analyze its chemical components. If they weren’t able to correct the issue soon, they warned, it would be hard to justify additional funding for the project. Ferguson wrote to Nelson Rockefeller asking for help, but while waiting for a response, he received word that Sloan Kettering and Merck were shuttering the project. “Feeble activity was irregularly demonstrated,” one doctor explained to the Rockefellers, “but so much less than that exerted by many other substances under study as to make further tests of the Ferguson material of low priority in our opinion.”

Ferguson blamed the dried plants. He enlisted Plaza, whose presidency had recently ended, to ask the Rockefellers for a $25,000 loan. On the advice of Sloan Kettering’s doctors, the family declined. Ferguson tried the NCI as well, according to The Son of Fergus, but the doctors there made clear that he would never get federal funding. His project, one cancer expert said, was “simply not scientific.”

Ferguson flew back to Guayaquil, only to learn that the Ecuadorean cancer society—the Sociedad de Lucha Contra el Cáncer, or SOLCA—had turned against him, too. According to Ferguson, the society’s founder held a press conference dismissing “the so-called research which Dr. Ferguson and a few of his misguided medical friends have made,” and describing Ferguson’s apparent successes with cancer patients as “a series of spontaneous regressions that would have taken place anyway with any treatment.” (SOLCA didn’t reply to a request for records of the press conference.)

Why SOLCA spoke out against Ferguson isn’t clear. Maybe, like the experts at NCI, SOLCA’s members had heard about Ferguson’s research failures and decided he was doing bad science. Perhaps the fact that Plaza, his benefactor, had left office in 1952 played a role. That mattered, certainly, as Ferguson sought to regain his footing in Ecuador; his contracts with hospitals, the military, and universities in Ecuador had dried up. A few months prior, the press had hailed him as a hero. Now, at least in medical circles, he was a pariah.

Ferguson reminded himself that the great physician Paracelsus was ridiculed in his lifetime. Louis Pasteur was attacked “until the day of his death.” If Merck and Sloan Kettering wouldn’t help him prove that the Shuar solution could save lives, he would find the evidence himself. With Ruth’s counsel, he decided that there was only one place to go. “We would move our entire family and all our scientific equipment,” Ferguson wrote, “into the Ecuadorian Eastern Amazon.”


The family relocated to Sucúa, near the settlement where Tangamasha lived. The town didn’t offer much more than a pair of missionary outposts—one Catholic, one evangelical—and a few muddy, unpaved roads that didn’t lead far. “The only way in or out,” recalled Patricia, the Fergusons’ daughter, “was by plane.”

The Fergusons landed on Sucúa’s grass runway on July 25, 1953. Their reputation in the area was still good from the assistance they provided during typhoid epidemic. Tangamasha’s friends and relatives “came from some forty miles in all directions to welcome us,” Ferguson wrote. With their help, the family built a huge oven from cement and brick and roasted a cow for a feast. Ferguson chose “a small hill about two hundred yards from the air strip” to construct his family’s compound. With dozens of local men and boys, he cut trees and gathered bamboo. The group staked out wooden frames for a house, a laboratory, and smaller buildings, including a clinic, a kitchen, and space for guests. They lashed together bamboo walls and thatched roofs with palm fronds. In a reflection of the family’s priorities, they poured a concrete floor for the lab, but not for the house.

Ferguson resumed treating patients during the day and staring into test tubes and microscopes at night. He worked long hours, trying to improve and standardize the formula for the head-shrinking fluid. Eventually, he eliminated another plant from the solution. He also decided that tempering the solution by shrinking an animal head wasn’t necessary after all.

Ruth helped in the lab while working as one of only two nurses in the area. When a baby was born, someone came running for Ruth. She stitched up cuts and set fractures when people fell or injured themselves. She administered injections—vaccines for children, vitamin boosts for pregnant women—and cared for those suffering from parasites or the flu. She gave out free antibiotics and other medications. “She was willing to help anybody, no matter what,” Patricia told me. Ruth often read Bible stories aloud to her patients. She once told a reporter that she wouldn’t trade her life in the jungle “for any other,” and defended Wilburn from critics who pointed out that he wasn’t really a doctor. “Who in science and medicine has made the great discoveries?” she asked. “Not the trained man, bound by rules, but the man who breaks them or has a lucky accident.”

The Ferguson children had to pull their own weight. “It was work, work, work,” Patricia recalled. She raised chickens, grew papayas, and roasted the family’s coffee. As she got older, she noticed that none of her neighbors lived in bamboo houses. They had solid roofs that kept out precipitation. The buildings on the Fergusons’ property, as one visitor observed, leaked water during the area’s frequent hard rains.

One of their neighbors was a teenager named Nicanor Sangurima—most people called him Nico. His father owned a cattle ranch. When the Fergusons came to Sucúa, Nico was about the same age as Ralph, and the two boys became friends. Patricia befriended Nico’s sisters. Nico remembers being impressed with her Spanish. Patricia spoke it perfectly, with an elegant accent.

Sometimes Nico stopped by the lab to use Ferguson’s typewriter. The glass tubes and machines fascinated him. But he was even more interested in Ferguson, who would raise his head to greet Nico and keep working. Nico had never met anyone who affected others the way Ferguson did. “People would go out of their way to accommodate him,” Nico told me. Ferguson seemed to expect it. “He never stood in line,” Nico said. “If he saw a long line, he would go to the front.”

To make money, Ferguson arranged with a travel agency to bring tourists to Sucúa. He asked Tangamasha and other Shuar to perform for visitors. “They sang their native poetic songs, danced all their exotic dances and if a tourist was a little slow or missed a shot they repeated it for them,” Ferguson later recalled. In 1956, the American ambassador to Ecuador brought Senator Bourke Hickenlooper to watch a Shuar ceremony and to tour Ferguson’s lab. Hickenlooper, a conservative Republican from Iowa, called it a “fascinating experience.”

Hickenlooper and Ferguson kept up a correspondence. With the senator’s aid, Ferguson planned another fundraising mission to the States. While he was in Washington, D.C., Hickenlooper helped him incorporate a nonprofit—the Ferguson Research Foundation. Ferguson also screened a short film he’d made about his life in the jungle. From the Beltway, he traveled across the country. He showed his movie at high schools and churches. In San Diego, he appeared on television. In New York, Nelson Rockefeller’s secretary turned him away. In Chicago, a department store magnate politely declined his request for backing.

Ferguson was a curiosity, but not an investment. By the end of the trip, he was penniless. He slept on buses and, once he’d made it back to Washington, scrounged enough cash to send a telegram to Ecuador asking for a plane ticket home.

After the trip, Ferguson worked harder than ever in his lab but also turned inward. He began to see threats around him. In his autobiography, he wrote of “many enemies” who tried to undermine his project. He feuded with a local evangelical missionary, accusing him of a “rabid campaign against my research.” By decade’s end, tourists had stopped coming, and there was no money left to continue the work.

Ferguson told his family that they were moving back to California. But Patricia, who was 16, said she wasn’t leaving. She and Nico were in love, Patricia said. It was a surprise to everyone except Patricia’s talking parrot, who always whistled when the couple were together.

Nico wrote Ferguson a letter asking permission to be Patricia’s boyfriend. Ferguson went a step further: He invited Nico to come with them to the United States. The young couple were married in June 1960, and in August, the now slightly larger Ferguson family flew to Miami.

Ferguson bought a Chevrolet station wagon, painted desert beige, and the clan set out for California, driving all day and sleeping in motels at night. Patricia’s parrot squawked in the back seat. Through the windows, she and Nico watched an unfamiliar country pass by.



For a while, the family lived in Southern California’s Inland Empire, where Patricia and Nico spent their days grinding, boiling, and distilling jungle plants on Ferguson’s behalf at a place called the World Life Research Institute. It was the passion project of Bruce Halstead, a young doctor and ichthyologist (fish scientist) with a knack for winning government grants. The institute was on 520 acres in a canyon. It had a research library and laboratories where as many as a dozen scientists worked at a time. When Patricia and Nico’s first son was born, Halstead covered the hospital bills.

One day, Ferguson abruptly announced that they had to leave the institute—it was going under. Nico later heard that Ferguson feared Halstead wanted to cut him out of the effort to turn the head-shrinking fluid into a marketable drug. But Halstead’s son, Larry, told me that couldn’t have been true—his father always spoke highly of Ferguson. About a year after World Life collapsed, when Halstead revived it on a smaller scale on his family’s property, he hung a photo of Ferguson on the wall.

Ferguson’s dreams were further thwarted when federal law changed in 1962. For the first time, the government would require manufacturers to prove that drugs were safe and effective before marketing them to consumers. Qualified experts would have to conduct clinical studies in which subjects gave informed consent. The Food and Drug Administration would set manufacturing standards and inspect facilities. According to an FDA administrator, the agency “was no longer a helpless bystander while unproven medicines were streaming into pharmacies and onto patients’ bedside tables.”

A doctor from Palm Springs had sometimes stopped by World Life to pick up bottles of the head-shrinking fluid. As far as Nico understood, he was using it on cancer patients. “He was having success with it,” Nico said. “He kept coming, asking for more.” Now, with stricter federal laws, the doctor stopped treating patients with the solution.

After 1962, the Ferguson family wandered. Ruth and Wilburn went back to nursing. “I usually worked the twelve-hour night shift,” Ferguson wrote in his autobiography, “and spent every spare moment of my time over the research records, translating the Spanish documentation and arranging the reports for potential sponsors, should we again have that opportunity.”

While Ferguson looked for donors, the younger generation looked for work. Ralph took classes at Loma Linda to become a histology technician. Gene was hired by a police department back east. Nico sold cars, then found a job as a machinist in aircraft factories near Los Angeles. For extra money, he sold cookware door-to-door. Patricia stayed home to raise their two sons. The generations remained close, living on the same street, and sometimes in the same house—like in El Centro, where almost everyone piled into my step-grandfather’s spare apartment.

Every few years, when Ferguson thought he saw a new opportunity, the family moved. Each time, Ruth left her job to pursue their larger goal. “She traveled with him, no matter what,” Patricia told me, because she “never had any doubts.” Curing cancer was as much her dream—and was furthered as much by her labor—as it was Wilburn’s.

One day in June 1969, Ferguson approached Nico with a $2,500 check in hand. He wanted his son-in-law to use the money to fly to Ecuador and get more plants. Ferguson’s research had been dormant for years. Nico and Patricia had their family, and a daughter on the way, and they were leading the normal life that being Ferguson’s daughter and son-in-law had once denied them. Why did Ferguson want to revive his experiments now? And where, Nico asked, had the money come from?

Ferguson explained that he’d found a new group of investors who’d offered him a contract to produce a sample of the solution for lab testing. Nico read the document and found that it dictated that the head-shrinking formula be put in escrow, which meant identifying the plants and the procedure for distilling them. Ferguson didn’t have patents or other protections. The way Nico saw it, the family would be giving up its only asset.

Ferguson told Nico that if he didn’t like the contract, he should come to a meeting with the investors and propose better terms. “We need somebody that can negotiate,” Nico replied. Someone, that is, who understood business.

Nico reached out to an old friend: Ken Williams, a former paratrooper and school principal. Williams had also been Nico’s boss when he sold cookware. Now he was the dean of San Antonio Commercial College. Williams had spent time with Ferguson over the years and knew about the cancer project. He agreed to help. The negotiations with the investors eventually fell through, but Williams proposed another idea. The fifth floor of his college was empty. If they set up a lab there, Williams said, the school wouldn’t charge them rent or utilities.

The Fergusons were up and running again, this time in Texas.


Wilburn and Ruth quit their nursing jobs in California, and Nico, Patricia, and their two sons flew to Ecuador to visit family. While he was there, Nico gathered more plants. With donations from the college’s students and teachers, Ferguson sent away for mice and implantable cancerous tumors from a laboratory supply company. He kept the mice in coffee cans with holes drilled into them.

Williams was appointed executive director of the Ferguson Research Foundation, the nonprofit Ferguson had incorporated with Senator Hickenlooper’s help. Williams brought a steady stream of donors to visit the fifth-floor laboratory. Money came in, enough to fly Nico to Ecuador on regular foraging missions. The Fergusons replaced the coffee cans with proper cages. They bought a centrifuge, glassware, refrigerators, compressors, a freeze dryer, and other equipment.

Making the solution was time-consuming, and Nico wondered if it could be simplified—maybe by removing more ingredients. Ferguson believed that each of the formula’s components had unique qualities that, when combined, made the perfect drug: A certain tree bark prevented inflammation, another plant elevated the patient’s mood, another killed pain, and so on. Cutting out plants might prevent a necessary synthesis from taking place. “I’d rather use a shotgun than a bullet,” Ferguson reasoned. Eventually, he and Nico compromised—they would hire a chemist to analyze and isolate the active chemicals in the solution so the recipe could be standardized once and for all.

The foundation hired a young postdoc named J. Rao Nulu, recommended by Burlage, Ferguson’s old friend from the UT pharmacy school. Nulu spent weekends at the lab with Nico. The foundation then brought on a local pharmacology professor named William Stavinoha to supervise animal testing part-time, and another postdoc, Arvind Modak, to assist him. The years in the jungle, the rejections and disappointments, the desperate fundraising missions—all of it had led Ferguson here. “This was the kind of research collaboration I had dreamed of,” he wrote, “but frankly did not expect to find.”

Soon, the foundation outgrew its borrowed space at the college and moved to a location near San Antonio International Airport. Now it had to pay rent. When combined with Nulu’s salary—he’d come aboard full-time—the foundation’s bills outpaced donations. Williams proposed converting it into a for-profit corporation. Selling shares could bring in capital, he said, and would make it an easier pitch to donors, since they’d earn a profit from any drugs that proved marketable.

The years in the jungle, the rejections and disappointments, the desperate fundraising missions—all of it had led Ferguson here.

Ferguson agreed. They named it Farma Corporation. By its articles of incorporation, Farma was authorized to issue 500,000 shares of stock. Williams gave a controlling stake to the Fergusons and himself and set out to sell the rest.

One of the first people to buy stock, according to Nico, was the doctor who’d once come to the World Life Research Institute to pick up batches of the solution. His name was William P. Aikin. At the time, he was probably the only American doctor who had used the formula on patients—and he believed it worked. He joined Farma’s board of directors. “Dad said if it was good,” Aikin’s son told me, referring to Ferguson’s formula, “it was worth a fortune.”

When Modak said he wanted to end his postdoc early so he could work with the foundation full-time too, Williams suggested they find more investors and really grow the operation. To do so, they needed proof that the treatment worked. Ferguson saw no reason to wait—he wanted to use it on patients. “The people are suffering now,” he used to say. But according to Nico, an FDA inspector visited the lab and made it clear that he would shut the facility down if the team treated any patients.

“Can I take patients in Mexico?” Ferguson asked.

“What you do in Mexico is not my business,” the inspector reportedly responded.

One of Farma’s investors contacted a friend in Torreón, in the Mexican state of Coahuila, who was a doctor and a partner in a medical clinic. The doctor’s name was Mario Gutiérrez Cárdenas, and he had a nephew, Arturo Gutiérrez Santos, who had just finished medical school. The clinic’s other doctors agreed to let Arturo, Mario, and the Fergusons use the facilities, as long as they took on only terminal patients. Because these people were likely to be poor, Ferguson insisted that the treatment be free. Farma would pay for everything.

Ruth and Wilburn moved to Torreón. Nico was tasked with driving batches of the extract down from the lab in San Antonio, where he and Patricia still lived. The trip took 12 hours, with inspections at the border, traffic stops, and plenty of mordidas (bribes). Later, Nico began flying the formula down by plane once or twice each week—he’d obtained his pilot’s license back in California. He used a twin-engine Cessna that Williams bought with a three-year mortgage, putting up the lab equipment as collateral.

Nico began to have doubts about Williams. Farma still had no revenue or marketable product. All it had was capital, which Williams raised by selling stock. The corporation was burning through money, but somehow Williams kept finding enough investors to keep the lights on. (He was a gifted salesman, according to his stepdaughter, Lucy Rix. “Ken could sell snow to the Eskimos.”) Every few weeks, it seemed to Nico, Williams awarded Wilburn, Ruth, or Patricia several thousand shares in Farma, and assigned himself a few thousand as well. “We need to keep the family in control,” Williams explained when Nico asked.

By family, Nico realized, Williams meant himself, too.


Early in the summer of 1970, Julia Cedillo, a 68-year-old woman in Juárez, crossed the border into El Paso for an appointment with a neurologist. She had a troubling set of symptoms: dizziness, vomiting, confusion. Most frightening of all, she was losing her eyesight. Lately, her field of vision had been limited to “seeing like a kind of little window,” recalled her daughter, Carmen Darancou Muñoz. “A flat little square. This square was closing, little by little, until the point that it was almost shut.”

The neurologist took a biopsy. When the anesthesia wore off and Cedillo woke up, she was told that she had an astrocytoma of the right parietal lobe—brain cancer. It was advancing, the doctor said, but the tumor was too large to remove without causing neurological damage.

Cedillo was an aunt of Ferguson’s partners at the clinic in Torreón. They asked the woman they called Tía Julia if she’d like to try Ferguson’s remedy. Cedillo said yes, and Darancou Muñoz left her job to travel with her mother to Torreón. “When I first arrived,” Cedillo later wrote, “I was in a wheelchair and partially paralyzed on one side of my body.” She was nearly blind, and slipped in and out of a coma.

Darancou Muñoz told me that during the first week at the clinic, Ferguson gave her mother “a little bottle.” It looked like it held cough syrup. The substance gave off an herbal smell and tasted bitter. But the very first dose her mother drank, Muñoz said, “started to open up that little window in her eyes for her.” By the fourth week of treatment, according to clinic reports, Cedillo was walking to mass every morning. Soon she could read the newspaper.

As a Farma board member, William Aikin heard about Cedillo’s progress. He pleaded with Ferguson and the Mexican doctors to use the extract in conjunction with surgery; Aikin believed that it would shrink tumors but not make them disappear. Nico remembered him saying, “You have to remove the tumor and continue with extract afterwards.” They should use the extract like they would chemotherapy, Aikin said.

Nico tried to convince his father-in-law to take Aikin’s advice, but Ferguson declined. Aikin grew annoyed. “You are trying to work miracles,” he reportedly said. Not performing surgery was naive—or worse.

But to Ferguson, Cedillo’s case suggested that the formula was curative. After eight months of treatment, she had none of her former symptoms. She eventually returned home believing that Ferguson had saved her life. According to Darancou Muñoz, the El Paso neurologist was amazed when he examined Cedillo again. “If there wasn’t an operation,” Darancou Muñoz recalled him saying, “where is the tumor?”

Cedillo lived for 23 more years, dying at the age of 91. For a long time, she sent Christmas cards to Ferguson, signed in elegant, old-fashioned cursive. To her mother, Darancou Muñoz told me, “he was like an angel.”


In July 1972, Nico had just returned to San Antonio with a shipment of plants from Ecuador. It had been a long flight, with a layover in Mexico, and he was tired. But no sooner did he get home than Patricia told him to get ready to leave again. Something was wrong with the corporation. The investors were meeting in Reno, Nevada, the next day, and he needed to be there.

Williams was so successful selling stock that the corporation had increased its total shares twice in three years. On both occasions, Williams issued most of the new shares to himself and the Fergusons, so they’d retain a controlling interest. But he’d failed to register over two million of those shares with the Texas State Securities Board, as required by law. Investors were worried that criminal charges could be filed against both Williams and Ferguson. A lawyer said that the best solution was to dissolve Farma and transfer its assets to a new organization. The company’s shareholders would have to consent. For good measure, the lawyer recommended incorporating the new entity in a different state. That’s why the meeting was called in Reno.

Nico, Ralph, and Gene joined the other shareholders. Wilburn and Ruth stayed in Mexico. At the meeting, lawyers proposed dissolving Farma and reincorporating in Nevada as Pharma Capital Corporation. The laboratory equipment, the airplane, and the rights to the secret formula would belong to the new entity. Everyone who had bought stock in Farma would receive an equivalent number of shares in the new company.

Everyone, that is, except the family. The Fergusons—and Williams—would get nothing. They would be removed from their positions at the firm.

According to Farma’s articles of dissolution, investors representing 1,905,779 shares voted in favor of the lawyers’ plan. No one voted against it. Aikin abstained, Nico recalled, after trying to persuade others to change their minds. But even Williams and the Ferguson family voted yes. “We all had no choice,” Nico said.

The attorneys placed an investor—an Iowa rancher with no scientific background—in charge of the new corporation’s research. In Torreón, Wilburn and Ruth, devastated, were forced to ask the patients they were treating to leave the clinic for good.



In July 2019, I found myself in Texas looking at an open fireproof box. Inside was an object the size of a grapefruit that smelled like old leather. I saw thick hair and a hole where an eye should have been—a rat had picked it away some years prior. The other eye was closed, its bushy lashes sealed by time.

It was one of Ferguson’s shrunken heads, stashed away for safekeeping by one of his remaining acolytes.

I’d come to Texas to meet Charles Mazinter, a real estate entrepreneur and former car salesman with dreams of finally proving Ferguson right. Mazinter met Ferguson around 1997. By then, Ferguson was in his nineties. His hair had grown long, Mazinter said, giving him an “Albert Einstein look.” The previous 25 years had taken a toll.

After Ferguson lost Farma in 1972, he spent much of the next year finishing his autobiography. The Son of Fergus was 423 pages long, and it combined his life story with lab results, photos of patients and their tumors, a history of the Shuar people, and copies of letters from his supporters. He mortgaged the Torreón house he shared with Ruth to print 100 copies bound in leather. He stamped the book as the property of the Fundación Incorporada de Investigaciones Ferguson de México and dedicated it “to my Sponsors Past, Present, and Future.” He mailed copies to Walter Cronkite, George H.W. Bush, and other powerful figures.

The bank eventually repossessed the Fergusons’ house, and the couple returned to California. For a few years, Wilburn again worked as a nurse. In 1977 he retired. He was past 70; Ruth was nearing it. They moved to Texas, where Patricia and Nico still lived. For the rest of his life, the old man wrote letters, still looking for support. He found an ally in a Hollywood composer named Phillip Lambro, who bought the rights to The Son of Fergus and tried to get movie studios to develop it. Meanwhile, without a laboratory, Ferguson imagined ways to improve his formula, writing up new extraction and distillation techniques on the back of stray documents.

In 1992, he was in the news again. Someone told him about Medicine Man, a movie in which Sean Connery plays an eccentric scientist searching for a cure for cancer in the Amazon. Connery and the film’s screenwriter, Tom Schulman, were both represented by Creative Artists Agency, and Phillip Lambro had sent an employee there a copy of Ferguson’s autobiography. Ferguson and Lambro believed they were being robbed. They decided to sue for copyright infringement—but it wasn’t a winning case. Lawyers representing Connery and Schulman produced documents showing that the movie was inspired by a different researcher in a different jungle: Daniel Janzen, a conservationist and evolutionary ecologist in Costa Rica. Schulman had known Janzen for years. The lawsuit went nowhere.

Mazinter entered the Fergusons’ lives a few years later. An acquaintance of his, Ann Gaspari, had married Gene, the Fergusons’ eldest child. While Mazinter was visiting their house one day, he heard a noise in another room. Ann said it was Gene’s dad, who was living with them. “So they bring out Wilburn,” Mazinter recalled, “and he sits down, and we start talking.”

Mazinter found Ferguson fascinating. He thought it was a shame that research into the head-shrinking formula had been cut short. After the visit, Mazinter started having odd experiences. Every time he turned on the radio or TV, the program seemed to be about cancer. One day at a mall in San Antonio, a woman he’d just met started crying while telling him about a relative who was dying of the disease. “I’m sitting here going, ‘Why are you telling me? What do I have to do with any of this?’” Mazinter said. “It became so ridiculous that I knew something was going on. Like it was God saying, ‘Do something with this.’”

He went back to Ann and Gene’s and told them he believed he needed to be part of Ferguson’s project. According to Mazinter, they had already decided to ask for his help. Ferguson wasn’t looking for another scientist. What the old man needed was an entrepreneur.

Ferguson, Gene, and Ann took Mazinter out for dinner at an oyster restaurant. Soon after, Ferguson gave Mazinter his files. “It was like the passing of the mantle,” Mazinter said. He took the gesture to mean that if anything was going to happen with the research, it was up to him.

Ferguson wasn’t looking for another scientist. What the old man needed was an entrepreneur.

Mazinter tried several times to revive the project, taking it to drug companies and investors. In 2001, he spoke with Corey Levenson, a pharmaceutical chemist and the senior director of ILEX Oncology, a cancer-drug developer in San Antonio. Levenson told me that he found Mazinter’s pitch compelling. “I wanted to believe this stuff was going to work,” he said. “If you look at the drugs that we use now for treating cancer, a lot of them come from plants originally. So it’s not that far-fetched.” Levenson reviewed the files Mazinter had inherited from Ferguson and was disappointed to find mostly anecdotal accounts of cures and old reports based on “antiquated rat models that weren’t really considered very predictive.” There were no randomized controlled trials, no formal toxicity tests, not even enough chemistry to know if the extract’s active ingredients had already been isolated and put to use in other medical treatments.

Still, Levenson was curious enough to ask for more information, and Mazinter produced what Levenson remembers as “a vial of brown goop.” It was the head-shrinking solution, prepared by Nico. Levenson and his colleagues ran a preliminary test on cancerous cells and found, as Levenson wrote to Mazinter at the time, “that the extract was able to kill the cells.” Promising, but not enough. According to Mazinter, Levenson proposed an arrangement: ILEX would put up the money to test the solution further. In return, ILEX would own 90 percent of any drug that came out of the research.

Mazinter turned the offer down. He believed he could do better. “Looking back at it now,” he told me, “I should have taken the deal.”

Levenson said that he didn’t remember offering Mazinter anything, though his boss at the time may have suggested a deal. “Given that there was no compelling animal data that was ‘fresh’ and the business opportunity was still pretty risky,” he wrote in an email, “I don’t imagine ILEX would’ve offered much for it.”

The preliminary test was as far as the research went. I asked Levenson if Ferguson could have been right—if the brown goop might itself be, or perhaps contain, an effective cancer treatment. “We don’t know,” he responded. “Nobody ever took it to the point where you could say yes or no.”

“It’s kind of a shame,” Levenson said, “because he might have had something.”


Some legends are true, and others—perhaps most—only reveal truths about the people who tell them and the cultures in which they’re told. Tom Schulman, the screenwriter, pointed out that Ferguson’s quest shares themes with many popular stories, from Lost Horizon to Juan Ponce de León and the Fountain of Youth. They’re all tales of “explorers really looking for things of value.” Cities overflowing with gold. Life-giving waters in the Florida swamps. A cure for cancer from shrunken heads. It all connects to “this mystery of what goes on deep in the jungle,” Schulman said, “and this sense that there’s knowledge and wisdom out there.”

Ferguson died in 1998, a year after Mazinter met him. Ruth had passed away four years prior. Gene and Ralph are gone now, too, along with Galo Plaza, Tangamasha, Ken Williams, and other people who supported Ferguson’s work. The widow of one of the doctors Ferguson worked with at the Torreón clinic keeps a little glass bottle of the head-shrinking extract. Her husband saved it as a souvenir. Julia Cedillo’s relatives remember the Ferguson family fondly, even if some of them questioned the business model of a corporation that treated patients for free.

The streets in Sucúa are paved now, and one of them is named after Nico’s father. The local population has grown. The hill where Ferguson’s laboratory once stood is covered with houses. “You wouldn’t even recognize it anymore,” Patricia said.

She and Nico maintain ties to family in Ecuador. Their kids have grown up, and Nico has retired. He visits Sucúa every few years; his last trip was just before the coronavirus pandemic exploded. He and Patricia say it’s harder than ever to locate the ingredients in the head-shrinking formula. Still, Nico told me, “The plants are there to be found.”

One is of particular interest to him—a flowering vine that Nico believes is the key to the fluid’s power, based on the research he did in Texas decades ago. Mazinter is convinced of it, too, but neither he nor Nico would tell me much about the plant in question. “I can’t reveal exactly what it looks like,” Mazinter said, “but I can tell you the flower on it is phenomenal.” I asked if he could at least reveal the color of the flower. That would give too much away, Mazinter replied. “I don’t know what other plants would be so distinctive with this color,” he explained. “It’s just regal. Royal. Gorgeous. Breathtaking.”

Nico referred to it as “Plant A.” At his father’s ranch in Sucúa, back when he was a boy, they considered it a weed. “It was all over,” Nico said.

Nico and Mazinter are focusing the hope that Ferguson nurtured his entire life on a weed. Mazinter imagines a future in which the old man he met at his friends’ home is hailed as a visionary. To make that happen, he needs to raise money. A lot of it. “You need a million just to start,” Mazinter said. He’ll have to gather plant specimens, if he can find them. Then he’ll have to hire a chemist who can isolate and stabilize the active ingredients. If he gets that far, he can try to patent what he finds. He’ll have to conduct research on animals, convince the FDA to approve clinical trials, and prove that whatever’s in the vine with the incredible flower is both nontoxic to humans and more effective than other drugs already on the market. Failure awaits at every turn, just as it did for Ferguson.

“If I could go back in time,” Mazinter told me, “I almost think I might push a button and say, ‘I wish I never heard about it.’ Because it has brought me nothing but hard work and grief. And it has drained my finances in a very bad way.”

Nico favors a different path. He hopes to do just enough research to demonstrate the weed’s potential and convince a university, an investor, or someone else to carry the project forward. He said he trusts Mazinter and wants to make sure they work together, but he’s seen where the dream of money can lead. “My father-in-law spent a lifetime trying to raise a million dollars,” he said.

Nico wants to start small. “If somebody says they’ll take a risk and donate $20,000, I’ll take it,” he told me. “Form a corporation, whatever. I’m 85 years old. I’m not going to see it through, but I’d like to start something.”

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