How Ivermectin Became a Belief System

The deworming drug is central to an improvisational, alternative medical subculture that was forming even before the pandemic.

Photograph of a bottle of ivermectin
Houston Cofield / NYT / Redux

Since fall 2021, Daniel Lemoi has been a central figure in the online community dedicated to experimental use of the antiparasitic drug ivermectin. “You guys all know I’m not a doctor,” he often reminded them. “I’m a guy that grew up on a farm. I ran equipment all my life. I live on a dirt road and I drive an old truck—a 30-year-old truck. I’m just one of you.” Lemoi’s folksy Rhode Island accent, his avowed regular-guy-ness, and his refusal to take any money in exchange for his advice made him into an alt-wellness influencer and a personal hero for those who followed him. He joked about his tell-it-like-it-is style and liberal use of curse words: “If you don’t like my mouth, go pray to God, because he’s the one that chose me for this mission.”

Last March, during an episode of his biweekly podcast, Dirt Road Discussions, he thanked his audience for their commitment to his ivermectin lifestyle: “I love that you guys are all here trusting my voice.” His group currently has more than 130,000 members and lives on Telegram, a messaging app that has become popular as an alternative social-media network. When Lemoi died earlier this month, at age 50, his followers found out via the chat. As first reported by Vice, Lemoi had given no indication that his health may have been failing. In fact, one of his last posts in the group was from the morning of the day he died: “HAPPY FRIDAY ALL YOU POISONOUS HORSE PASTE EATING SURVIVORS !!!”

Members of Lemoi’s family did not respond to requests for interviews, but according to his obituary, he was a heavy-equipment operator for a naval-engineering company. In the weekly podcast-style chats he hosted on his Telegram channel, he described working on the waterfront of the Narragansett Bay. He shared every detail of his ivermectin story with followers, starting on a Friday in August 2012 when he first started suffering from vertigolike symptoms. This kicked off a labyrinthine journey through the medical system, involving, he said, many huge courses of antibiotics, bouts of extreme illness and pain, and a significant financial burden. (“And alone, living alone, like this whole thing—it was just me,” he explained in a chat recorded in November 2022.) Finally, in January 2017, a doctor specializing in Lyme disease prescribed Lemoi hydroxychloroquine. He was shocked to learn that it would cost him $288 a month. “So I had no choice,” he told his followers. “I had to go with Plan B.” He got the idea to take ivermectin from a friend’s daughter, who was studying to be a veterinarian and had, according to Lemoi, written a paper about the genetic similarities between horses and people.

After Lemoi’s death, whoever took over the Telegram chat wrote to the group that “his heart was quite literally overworking and overgrowing beyond its capacity, nearly doubled in size from what it should have been.” Previously, Lemoi had claimed to have no side effects from ivermectin except for “herxing”—a term borrowed from the world of chronic Lyme disease, which he used to describe symptoms such as dizziness, chills, fatigue, sweating, headaches, and blurred vision. All of these, he told his audience, were temporary. Although ivermectin has not been cited as a cause of death, Ilan Schwartz, an infectious-disease expert at the Duke University School of Medicine, explained that it could have contributed to Lemoi’s health problems. “Incorrect use—mostly encountered in the last few years when people self-medicate, often with veterinary formulations of the drug—can cause damage to a wide range of organs, most notably the brain and gastrointestinal tract,” he told me. “Cardiovascular effects are occasionally seen, mostly low blood pressure and fast heart rate.” Regardless, the Telegram group has continued its daily routine of pro-ivermectin, antipharma posting—a sign that fringe content will continue to bloom on the fractured social web.

Ivermectin gained national attention during the pandemic, when it was touted by some Republican lawmakers as a possible treatment for the coronavirus—but Lemoi had already spent years self-administering the medication in the version intended for large mammals. “I still haven’t found anything the 1.87% horse paste won’t or can’t handle,” he wrote on the “About” page of his website, referring to a common formulation of the drug. “Except if you break a bone or fall out of a window!” Lemoi said that he’d gone off his prescriptions and that ivermectin was the only thing he needed to feel better than he had in years. He’d mostly kept his treatment to himself, until the pandemic changed everything. “I literally felt hands on my back pushing me forward because the media was talking about how bad ivermectin was,” he said in the chat from last November. He recommended the drug to people he knew, then to people on Facebook. “Facebook turned into Telegram, turned into this chat,” he summarized.

Lemoi’s fans have promised to keep his legacy alive. In the Telegram group, they’ve shared “Dannyisms” like “You have everything you need in the chats.” And in the comments on his online obituary, hundreds of group members have left condolences and thanks: “We were so blessed by his voice and tender heart,” one reads. “Ivermectin forever.” “My whole take on Danny is he’s just like me—he is a truth seeker,” one member, Diana Pilkington Barry, told me, when we spoke after his death. “I hold him in very high regard,” she said. “He was a pretty remarkable man.” She admired him for coming up with his ivermectin regimen and then sharing it with other people, and for the broader anti-establishment worldview he represented. “It’s a belief system I’ve now adopted,” she said.

By the time Lemoi started his Telegram group, in November 2021, ivermectin and its rapid politicization had become inseparable from the pandemic. In April 2020, when an early lab test had seemed to indicate that ivermectin could be used as a possible COVID-19 treatment, the FDA had warned Americans not to self-administer versions of the drug “intended for animals.” Later that year, Republican Senator Ron Johnson of Wisconsin had invited a pro-ivermectin doctor to a Senate hearing, where that doctor referred to the drug as a “miracle.” (Johnson has since emerged as a vocal anti-vaxxer.) Clinical trials never found good evidence that human formulations of ivermectin were useful for treating COVID-19, and experts have continued to warn that formulations created for animals are dangerous to people. Some high-profile Republican lawmakers went to bat for the medication despite clear and consistent warnings from physicians, and many state-level legislators pushed for new laws that would protect doctors who prescribed it from censure or liability. Since then, semi-infamous groups of renegade doctors and nurses have continued pushing it. As reported by The Washington Post, a group of doctors who call themselves the Frontline COVID-19 Critical Care Alliance has recently started recommending ivermectin to treat the flu and RSV as well.

The members of Lemoi’s group are not solely focused on the coronavirus. Many—as Lemoi did—use horse-grade ivermectin in a misguided attempt to treat the symptoms of Lyme disease, cancer, anxiety, depression, and other maladies. Some, like Barry, take it preventively in hopes of strengthening their immune system and avoiding brushes with the “evil” pharmaceutical industry. The chat is also not only about ivermectin. It has an anti-vaccine, right-wing bent—a quick scroll brings up homophobic memes; a graphic, Photoshopped image mocking Nancy Pelosi; and a post explaining how unvaccinated people could inadvertently “contaminate” their blood by having sex with a vaccinated person. But the (incorrect) idea that unites the group is that most diseases are caused by parasites, and that members can prevent almost all illness by following the regimen that Lemoi created.

Though Lemoi’s experience with ivermectin originally had nothing to do with COVID-related conspiracy theories, it seems to have steered him in that direction over time. In the last episode of his podcast, posted on February 26, he spoke about “the biggest red pill the world is ever going to swallow.” He was convinced that the pharmaceutical industry wants to keep people in poor health, and that ivermectin use was considered fringe only because the powers that be want to keep people full of parasites.

At this late stage in the pandemic, ivermectin is still attracting new attention through social platforms. Recently, in a YouTube video with 1.7 million views, the mega-popular podcaster Joe Rogan talked about using it and feeling frustrated that the media keep referring to it as “horse dewormer” (though it literally is one). Tracking the extent of its use is also getting harder. Some of the biggest and most unruly Facebook groups promoting ivermectin have been removed, but many groups remain that are smaller, private, more careful about avoiding automated content moderation, and more selective about who they admit. (My request to join one of them was immediately denied.) The conversation has moved out of mainstream spaces and into more specialized communities that were originally organized around other shared attitudes or experiences. On Reddit, ivermectin discussion mainly appears in the infamous, openly paranoid forum r/conspiracy, or in the newer forum r/covidlonghaulers, populated by people dealing with long-term COVID symptoms and experimenting with whatever treatments sound like they could possibly help. Like the #DiedSuddenly conspiracy theory, ivermectin also has a big presence in the alt-tech ecosystem—Gab, the far-right platform, runs ads for the drug in its main feed.

The continued misuse of Ivermectin reminds us that a dangerous idea doesn’t go away when it’s removed from the center of attention on major social-media platforms. In fact, as some researchers have argued, it may become more concentrated—a greater source of identity and of in-group self-definition. “Shared experience that is not acknowledged or appreciated by mainstream communities is a very powerful source of community-building,” Drew Margolin, an associate professor at Cornell who studies online communication and alternative health groups, told me. And though much pressure has been put on social-media companies to prevent the proliferation of medical misinformation in the past three years, a platform like Telegram, which is not end-to-end encrypted by default but does present itself as a place for private, unmoderated messaging, offers an easy alternative.

Robert Aronowitz, a professor of history and the sociology of science at the University of Pennsylvania who has studied the controversy around Lyme disease, has been following the tension between medical authority and anti-authority medical activist groups since the 1970s. A lot of these groups involved improvisational home remedies, influencers who became icons, and a strong sense of community. “Many of us journalists, doctors, blame social media for inciting distrust in medical authority and allowing communities of people to form,” he told me. “I’m not saying social media doesn’t have a role, but in terms of ultimate cause or origins, it has very little to do with it.”

If anything, the internet may have helped different existing groups find one another and comingle. When Aronowitz was studying Lyme disease, he said, there was no overlap between that community and the anti-vaccine movement—“there weren’t obvious alliances or even sympathies.” (The alliance now is not total—many Lyme activists also promote COVID-19 vaccination.) Nor was there a hint of polarized “left-right politics.” Today, the anti-vaccine movement has made so much progress at co-opting other alternative health movements, and has been so thoroughly claimed by the political right, that this is hard to imagine.

It’s even harder to imagine anti-vaxxers engaging productively with a faction of the pro-vaccine mainstream that has begun to build a morally superior identity around its acceptance of science. Just look through the self-satisfied tweets about Lemoi’s death: “I just want to thank Danny Lemoi for his hard work in the extremely competitive field of ‘Natural Selection,’” a typical post reads. Another person wrote: “Here lies Danny Lemoi, who fucked around and found out.”