The drug is now marketed and sold across the state in roadside shops and small-town strip malls with little oversight from health authorities. Highway billboards advertise ivermectin as “Available Without a Prescription in Tennessee!” while dozens of pharmacies offer highly concentrated pills, sometimes at 10 or 20 times the potency of a standard tablet.
Ivermectin is a Nobel Prize-winning, generally safe drug approved by the FDA for treating parasitic diseases in humans, which can generally be done with a single dose of three or four prescription-strength tablets. It is also used as a dewormer for horses and other livestock.
Its popularity surged during the pandemic as fringe doctors and anti-vaccine activists promoted it as a treatment for Covid. Clinical trials have shown that ivermectin is not effective against Covid.
Nonetheless, it has since become a symbol of resistance against the medical establishment among conservatives and followers of the Make America Healthy Again movement, championed by Health and Human Services Secretary Robert F. Kennedy Jr.
Timothy Caulfield, a professor at the University of Alberta who studies health misinformation, said ivermectin became an “ideological flag” during the Covid pandemic, opening the door for influencers to push the drug for other ailments to a “captured audience” even without proof it works for those conditions.
“This is really about profit. This is about political identity. This is about creating distrust in the existing biomedical community. This is about money,” Caulfield said in an interview with ABC News, which partnered with KFF Health News to report on ivermectin.
After a hantavirus outbreak on a cruise ship earlier this year, unproven claims that ivermectin is effective against the virus have been spread by some popular social media accounts and right-wing figures, including former congresswoman Marjorie Taylor Greene. The World Health Organization says it has seen no research that shows ivermectin is an effective hantavirus treatment.
Tennessee’s ivermectin bill was shepherded by a Republican supermajority in 2022. Its passage blindsided state medical officials and handed a victory to medical groups that spread Covid misinformation.
Some pharmacy websites now offer the drug as a treatment for Covid, “long haul vax symptoms,” diabetes, or cancer — despite no evidence of its effectiveness for those purposes — while the new law largely gives pharmacists immunity from lawsuits or professional sanctions related to ivermectin.
The law was also a harbinger of legislation to come: More than two dozen states have since considered look-alike bills that would make the politicized medication available without a requiring a doctor visit.
John Mafi, a UCLA internal medicine physician who has studied the rise of ivermectin among cancer patients, worries it will lure people away from proven treatments. He co-authored a new study identifying a sharp increase in prescribing rates for ivermectin and another antiparasitic drug, particularly in the South. The rise followed a January 2025 episode of the “Joe Rogan Experience” podcast in which actor Mel Gibson claimed ivermectin and other drugs cured three friends with stage 4 cancer.
“It’s going back to 19th-century quack science,” Mafi said about off-label use of ivermectin. “It is alarming that I’m seeing this really unproven therapy being touted to so many potentially vulnerable Americans.”
The FDA says ivermectin can be dangerous in large doses. Tennessee has seen a small but concerning rise in signs of overuse. The Tennessee Poison Center, which fields calls from people exposed to drugs or toxic substances, received more than 60 calls for possible ivermectin poisoning in 2025, the most since 2021. They included reports of vomiting, blurred vision, neurological problems, and difficulty walking.
“People are taking this because they just feel unwell. It’s almost like a panacea now,” said Rebecca Bruccoleri, the poison center’s medical director. “I’ve heard rumblings on the internet of using ivermectin for an alternative cancer treatment, and we’re seeing it definitely in here.”
Pharmacist Paul Hughey has dispensed ivermectin under the new law at two Tennessee pharmacies: Mt. Juliet Pharmacy and Compound Rx. He estimated that “up to 20 people in a week” are buying ivermectin but that peak demand was double or triple that amount.
For years, Hughey said in an interview, customers have relayed emotional “testimonies” about the drug healing the sick, “especially with the cancer patients.”
“I’ll get a doctor call in and they say: ‘Guess what. So-and-so is cured.’ And it’s just amazing to hear that. So anybody who doubts that,” Hughey said, “I don’t really know that they’re practicing medicine. I think they’re just following the narrative.”
‘I’ve taken bucketloads of this stuff’
The linchpin of Tennessee’s ivermectin market is Denise Sibley, a conservative doctor who was instrumental to the creation of the 2022 ivermectin law. She has inked agreements with pharmacies across the state empowering them to sell the drug.
Tennessee’s law allows pharmacies to dispense ivermectin without a specific prescription for each patient, through a “collaborative pharmacy practice agreement” with a doctor who provides what is functionally a pre-written, nonspecific prescription for all potential customers.
In podcast interviews, Sibley has said she has made as many as 40 of these agreements with Tennessee pharmacies, which she said forward her the paperwork on each ivermectin customer. Before selling the drug, pharmacies are required to ask customers questions about medical conditions and medications that could cause complications if taken with ivermectin. Afterward, the collaborating physician also is expected to receive a record for each person who purchases ivermectin.
“We literally have folks coming from all over the world to get our ivermectin,” Sibley said on the “Common Sense MD” podcast in February 2025. “As the collaborator for these pharmacies, I get every person’s sheet.”
“They’re from every state,” she said. “They’re from Canada. They’re from Europe.”
Sibley did not respond to requests for comment.
KFF Health News has independently confirmed that Sibley signed agreements with at least 10 pharmacies. The agreements say pharmacists shall dispense ivermectin only in Tennessee, where Sibley is licensed, although one of those pharmacies said friends and family in Tennessee can “facilitate sending the medication.”
Hughey, the Tennessee pharmacist, said Sibley had prescribing agreements ready to go when the law was enacted. He credited her with advancing ivermectin sales throughout the state.
“Had Dr. Sibley not stepped in and really pushed forward, there’s no telling how hard it would have been,” Hughey said. “It would have been a lot less widespread.”
Sibley also works with Children’s Health Defense, the Kennedy-founded group that has become one of the nation’s most influential anti-vaccine organizations. In podcasts, Sibley has referred to the Covid vaccine as a “bioweapon” and “the most toxic substance that’s ever been produced.”
Separately, she testified before Tennessee legislators in 2024 about an alleged plot to change the weather and block sunlight. The New York Times then included her in a story about conspiracy theorists.
Sibley has said in podcast interviews that she was told by God to treat Covid patients. She said she has advocated for ivermectin ever since.
“God agrees with what I’m doing,” Sibley said in 2023 on the podcast “Tomi Lahren Is Fearless,” which is recorded in Nashville. “I wake up every day and I say: ‘Yes, sir. I’m reporting to duty.’”
In legislative and government hearings throughout 2022, Sibley testified that she had treated around 4,400 people with ivermectin, including some Tennessee lawmakers, all without taking payment. Sibley described ivermectin as “a wonder drug” and said making it more available “would help me to save lives.”
“I’ve taken bucketloads of this stuff myself,” Sibley said in one such hearing. “I feel like I’ve been a good test subject.”
Sibley has said she dispenses ivermectin using treatment guidelines developed by Paul Marik, who in 2020 co-founded the Independent Medical Alliance, a medical group that has promoted ivermectin as an effective treatment for Covid, flu, RSV, and cancer.
Some Tennessee pharmacies now follow those protocols, too. The protocols recommend patients take 1.5 to five times as much ivermectin as is normally prescribed to treat parasites, with the dose taken for days or weeks instead of just once.
Marik and other ivermectin proponents sued the FDA in 2022 after it discouraged the use of the drug for Covid by tweeting: “You are not a horse. You are not a cow. Seriously, y’all. Stop it.” The agency settled the lawsuit with no admission of wrongdoing and deleted the viral tweet in 2024.
The American Board of Internal Medicine has revoked Sibley’s and Marik’s board certifications but declined to explain why. Sibley still holds a Tennessee medical license; Marik is based in Virginia and is not licensed. Sibley and Marik each opposed the internal medicine board’s actions.
In response to questions from KFF Health News, Marik, through an Independent Medical Alliance spokesperson, said medical science benefits from “open discussion of ideas and treatments.”
“Many independent doctors have reported that treatments like Ivermectin, in conjunction with traditional treatments, are showing promise. These ideas should be explored,” alliance spokesperson Lynne Kristensen said in an emailed statement.
Marik testified in favor of Tennessee’s ivermectin legislation in 2022, telling lawmakers that it is necessary because people would otherwise buy animal-grade ivermectin in stronger dosages meant for livestock.
“They’re buying ivermectin from farm stores. We don’t know the quality,” Marik said at a March 2022 legislative hearing on the Tennessee bill. “So this would prevent that from happening.”
Tennessee does not track its ivermectin market
Arkansas, Idaho, Louisiana, and Texas enacted similar laws in 2025, and legislation that makes ivermectin available without the need for a doctor visit has been introduced or debated in at least 24 other states, according to a KFF Health News analysis. That means half the country could be following Tennessee down an unlit path, because no one knows the full scope of its ivermectin market.
Tennessee does not effectively track which pharmacies offer ivermectin this way, and the state government has been unable to produce some foundational documents that pharmacies are legally required to file before they sell the drug, according to a KFF Health News investigation.
Doctors and pharmacies are required by law to notify the Tennessee Department of Health when they sign agreements that allow ivermectin to be dispensed without patient-specific prescriptions, although it is not clear whether this consistently occurs.
In response to a KFF Health News public records request for those ivermectin notifications filed by pharmacies, the agency over three months produced records from only 12 pharmacies, half of which have agreements with Sibley. The agency said it did not locate records related to at least 13 others that KFF Health News has identified as selling ivermectin without requiring individual prescriptions.
Department of Health spokesperson Dean Flener said the agency would not answer questions about whether or how it regulates ivermectin or the pharmacies that distribute it.
Tennessee has said it does not track how much of the drug is sold in the state, and the amount is not well captured by federal or insurance data sources. That’s because the drug is often sold at compounding pharmacies, which make customized medications that are not FDA-approved and rarely covered by insurance. Drugmakers and wholesalers did not respond to questions about how much ivermectin they supply to pharmacies in the state.
Even the Independent Medical Alliance, one of ivermectin’s biggest cheerleaders, says it doesn’t know how much is flowing through Tennessee.
States are getting pressure from clinicians ”who have had success with the use of ivermectin,” said IMA President Joseph Varon, a physician based in Houston. “That’s what happened in Texas, and that’s what happened in Tennessee.”
‘An unproven, potentially unsafe drug’
Once signed by Tennessee Gov. Bill Lee, the state’s ivermectin law took effect immediately — even before the state’s physician and pharmacy licensing boards created rules to guide the process, which Tennessee law also requires.
Some board members were shocked.
“We’re talking about an unproven, potentially unsafe drug,” Shant Garabedian, a doctor on the state’s Board of Osteopathic Examination, said of off-label ivermectin use during a 2022 meeting. “It’s already law. Somehow it passes without our sort of input.”
In meetings that followed, at least five members of Tennessee’s medical boards voiced concerns about the law beyond safety and efficacy. Some said pharmacists could overcharge for a drug that normally costs pennies per pill. Some worried that a loosely regulated, cash-based ivermectin market might attract shady characters, especially because the law also shields prescribers from ivermectin-related civil lawsuits.
“This involves no clinical engagement,” Melanie Blake, then-president of the Board of Medical Examiners, said during a 2022 meeting. “If they’re exempt from liability as well, I hate to think of things that individuals could do just to make money, but this would be one.”
The boards eventually enacted regulations affirming that ivermectin could be dispensed without any diagnosis. Board members said the law left them no choice.
“This is more of a situation where, legally, the legislature has decided for us,” John McGraw, another board member, said in a 2023 meeting. “This has sort of tied our hands in a lot of ways.”
The first known sale under the new law occurred in May 2022 in Sibley’s home of Johnson City, a city of about 74,000 people in northeastern Tennessee. According to a news release, Sibley entered into a collaborative agreement with pharmacist Josh Harrison at The Compounding Lab, which dispenses drugs for people and animals.
The first customer was Bernadette Pajer, an anti-vaccine activist who has worked with Children’s Health Defense. In a 2024 episode of the Nashville podcast “Rebunked With Scott Armstrong,” Pajer said Sibley was a medical adviser for the group and described the first ivermectin sale.
“On that day, she was the doctor, he was the pharmacist making the sale, and I was the first customer,” Pajer said. “So that was pretty cool.”
Ivermectin pharmacies have spread across the state. In the suburbs of Nashville, Roman Pharmacy advertises ivermectin on at least four billboards along Interstate 65, and its website is mostly focused on the drug. Outside Knoxville, Fresh Pharmacy allows customers to order ivermectin for multiple sclerosis and Parkinson’s disease, or “to use it to detoxify.”
Roman Pharmacy did not respond to interview requests. Fresh Pharmacy declined an interview.
In Chattanooga, the Medicine Counter pharmacy says on its website that ivermectin should be taken “only as prescribed by your healthcare provider.” And yet the pharmacy sells some of Tennessee’s most potent ivermectin available without a prescription from a doctor — up to 21 times as strong as a standard tablet, for nearly $19 per pill — according to the KFF Health News analysis.
Himanshu Patel, Medicine Counter’s head pharmacist, declined to be interviewed. He said in an email that the pharmacy operates in a “very competitive market” and that its strongest pills were below the maximum dose for humans evaluated by the FDA for safety purposes.
And then there is Compound Rx, which, in addition to selling ivermectin in its store, has built a website in preparation to ship buy-one-get-one-free pills nationwide. The site, which is in “test mode,” cannot currently make any sales. It also asks customers how they heard about the pharmacy, with a dropdown menu of answers that features right-wing figures such as Donald Trump Jr., Steve Bannon, Laura Ingraham, and Kevin Sorbo.
Who is not listed as an option? Your doctor.
Hughey, the Compound Rx pharmacist, said he wasn’t involved with the website, which he said may never launch.
The highly concentrated pills are a concern for Tennessee state Sen. Richard Briggs, who worries lawmakers have created a “dangerous” ivermectin market rife with “misleading advertising” about what the drug can actually do.
Briggs, who is a surgeon and the only Republican who voted against the ivermectin bill in 2022, said he planned to introduce legislation to rein in the sale of ivermectin when lawmakers reconvene in 2027.
“But it may be a hard sell, because with the anti-vaxxers and some of these other folks,” Briggs said. “We don’t base a lot of things that we do on science, data, or facts. To a lot of folks in the legislature, the facts are just an inconvenience.”
‘Enough trouble with ivermectin’
Lawmakers in at least seven states have considered ivermectin legislation this year, including Alabama, Florida, Oklahoma, and South Carolina. If enacted, these bills would allow people to obtain ivermectin without an individual prescription, like in Tennessee, or make it available over the counter.
Kennedy praised such legislation at an event in Texas last August.
“I think it’s a really good bill,” he said of Texas’ ivermectin legislation, according to The Texas Tribune. “I think Americans should have the choice.”
But proponents have hit roadblocks. A Utah bill failed to advance out of the state House this year. In Oklahoma, some lawmakers have put up a fight.
“I’m a scientific person. I need to see some research and some data that shows what we’re treating,” Oklahoma state Rep. Cynthia Roe, a Republican and nurse practitioner who opposes the state’s ivermectin bill, said in an interview. “And God forbid somebody start giving it to their kid.”
Back in Tennessee, one of the medical boards that was alarmed when the law was enacted in 2022 started to distance itself from ivermectin altogether.
In January, the Board of Medical Examiners grappled with how to punish Ricky Lee Jackson, a doctor who was licensed in Tennessee and had been sanctioned and fined by Washington state’s medical commission. The Tennessee board normally mirrors punishments from other states without hesitation. But the Washington case centered on Jackson prescribing ivermectin for Covid, which in Tennessee no longer required a patient to see a doctor.
After a debate, the board voted to reprimand Jackson — but told its staff to ensure the public record made no mention of ivermectin.
“This board has been in enough trouble with ivermectin,” member Keith Anderson said, according to a meeting recording. “Maybe we ought to just leave that out.”
Nashville Public Radio journalist Blake Farmer and Tennessee Lookout reporter Adam Friedman contributed to this report.
KFF Health News is a national newsroom that produces in-depth journalism about health issues and is one of the core operating programs at KFF—an independent source of health policy research, polling, and journalism. Learn more about KFF.
This article first appeared on KFF Health News and is republished here under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.