After the third day of squirting an experimental drug up his nose, Dylan Meetze felt horrible.

“It was like I was underwater, like it took the most to do anything,” he said.

Meetze stopped taking the drug but endured fatigue and anxiety for months afterward, and his eyes and muscles twitched, he said.

He had taken BPC-157, a peptide drug popularized by podcasts about wellness, longevity, and what’s called “body optimization.” “Peptide” is a general term for substances that are smaller than proteins but composed of the same building blocks. Dozens of peptide drugs, including insulin and GLP-1 weight loss medicines, have garnered approval by the Food and Drug Administration. But BPC-157 and many others have not because they haven’t undergone clinical trials.

This fact hasn’t stopped online influencers from promoting them as remedies for muscle injuries, gut issues, covid, and more. Use of BPC-157 is growing in the U.S., particularly among white males, according to a new analysis of millions of de-identified electronic health records. Since 2020, the analysis, which hasn’t yet been published in a peer-reviewed journal, found that more than 1,000 people told doctors they had used the drug.

Meetze said he decided to take BPC-157 after listening to Andrew Huberman, a Stanford neuroscientist with more than 16 million followers on YouTube, Instagram, and TikTok, who talks up peptides frequently on his podcasts. Studies in mice suggest that BPC-157 helps muscles heal and has “very high safety profiles,” Huberman has said, “at least, with respect to the lethal dosing.” His guest on one episode, Craig Koniver, a doctor who sells peptides through his wellness clinic, called BPC-157 “super safe” and recommended it for “anyone who’s working out on a regular basis.” Koniver did not respond to requests for comment.

Huberman didn’t respond to multiple queries from KFF Health News, but an automatic reply linked to a disclaimer on his Huberman Lab website that says the podcast doesn’t constitute medical advice: “Any reliance on information provided through the podcast is solely at the user’s own risk.”

Hoping BPC-157 might help him advance as a weightlifter, Meetze said he bought the drug last year from an online vendor, Researchem. A chemical supply company with that name sells experimental peptides through its website, warning that the substances are “solely for laboratory research” and are “not intended for human consumption.” (It lists an address in Hillsboro, Oregon, that corresponds to a shared office space. A receptionist at the space said Researchem wasn’t registered there, and multiple queries from KFF Health News to the email address listed on the website went unanswered.)

Companies are required to warn that experimental peptides, which haven’t been approved by the FDA, are for research use only. But many companies may soon be permitted to drop the warning because of a push by health secretary Robert F. Kennedy Jr. to lower barriers to their use. He and other leaders of the Make America Healthy Again movement have promoted peptides as a way to improve the country’s health.

On the social media platform X, before he took the helm at the Department of Health and Human Services, Kennedy vowed to end the “aggressive suppression” of “peptides, stem cells, raw milk” and “anything else that advances human health and can’t be patented by Pharma.” (In fact, peptides are heavily patented.)

He has repeated the pledge since taking office. On Joe Rogan’s podcast early this year, Kennedy said he was a “big fan” of peptides and wanted to make many of them “more accessible.” On a podcast with the co-chair of the MAHA Action committee, Gary Brecka, Kennedy said the FDA’s role should be to assess science, “but not tell people and not tell physicians what they can and cannot prescribe.”

“If you want to take an experimental drug,” he added, “you ought to be able to do that.”

This summer, Kennedy’s health department appointed doctors with financial stakes in the peptide industry to a panel that advises the FDA. At an FDA meeting in July, the new appointees voted to ease restrictions on six experimental peptides, including the trendy compounds BPC-157, TB-500, and MOTS-c. Specifically, they advised adding these peptides to a list, called 503A, that would allow specialized pharmacies to make the drugs for human use, even though the FDA hasn’t approved them.

In an email, HHS spokesperson Emily Hilliard wrote that every committee member satisfies the FDA’s ethics requirements. “FDA — not podcasts or politics — determines which substances qualify for inclusion on the 503A Bulks List,” she wrote. The FDA has yet to issue a final decision.

The vote went against FDA scientists who presented research on the six peptides, concluding there wasn’t enough evidence to show they improved any condition. Furthermore, the scientists highlighted a potential for liver damage, allergic reactions, or other serious consequences.

“People are saying this is about medical freedom — putting decisions back in the hands of patients,” said Reshma Ramachandran, a regulatory science researcher at Yale School of Medicine. “But what we see in practice is that incentives aren’t actually centered around patients. They’re centered around selling products.”

Scientists also warned that drugmakers would be reluctant to invest millions of dollars into clinical trials on peptides if they could be sold without FDA approval.

“The chances of clinical trials getting done now are diminished,” said Eric Topol, executive vice president of Scripps Research, a biomedical science institute in San Diego. “We will have more people who are prey to predators that will sell, sell, sell.”

A lack of data leaves consumers in the dark.

Meetze sought help on Reddit, where people post about pain, headaches, vision problems, and a lack of motivation after taking experimental peptides. Peptide enthusiasts often comment on these posts with skepticism, attributing a person’s problems to contaminated products, preexisting conditions, or misuse of the drugs. The online vitriol in the Reddit conversations can be intense, so Meetze welcomed an invitation to join a private group on the social platform Discord in which people with BPC-157 side effects tried to figure out what happened to them and how to fix it.

“There are millions of success stories with these peptides,” Meetze said, “but no one wants to believe that this wrecks some of our lives.”

Wolverines and Migraines

One member of the private side-effects group, a 46-year-old software engineer named Dominik E., said he got an excruciating migraine within days of taking BPC-157 with TB-4, another unapproved peptide — a combination called the “Wolverine Stack” because of its purported ability to heal wounds rapidly, like its namesake Marvel superhero.

“My left eye started throbbing really badly, and the left side of my face became numb,” he told KFF Health News, which agreed to only partially identify him and others interviewed for this article who were concerned about divulging sensitive health information.

After two months of migraines, Dominik said, the pain eased, but his face felt inflamed. “It is a total nightmare,” he said.

“I’m afraid how people will judge me,” said Lois S., a woman who works at a Michigan elementary school. She hoped BPC-157 and another unapproved peptide, retatrutide, would help with weight loss, but she stopped taking the treatment when she felt pain.

“I sought out this substance from a lab that clearly labeled it not for human use, purchased a syringe, and injected this in my kitchen,” she said. “That belies all logic about what a normal person would do.”

Peptide proponents argue that shoddy manufacturing — not the peptides — causes harm. Therefore, they say, the FDA must protect the public by allowing doctors to prescribe peptides made for human use by pharmacies that specialize in compounding medicines. Typically, compounding pharmacies manufacture alternatives to FDA-approved drugs so a patient can, say, get a liquid version of a drug that the original manufacturer makes only as pills.

Adding unapproved peptides to the FDA’s list of compoundable drugs would mark a departure from the list’s purpose, said Peter Lurie, a former FDA official who now directs the advocacy group Center for Science in the Public Interest. He noted that federal and state oversight for compounding pharmacies is often lax, and they’ve been cited for contamination.

Furthermore, he added, the move would mislead consumers into thinking they’re buying drugs backed by clinical trials. People promoting peptides often point to promising laboratory research as evidence. Rats with spinal injuries regained tail mobility after BPC-157 injections, for example, and old mice given the experimental peptide MOTS-c could run longer. On average, however, fewer than 10% of substances that show promise in animal studies prove effective in clinical trials.

“A lot of this pseudoscience stuff sounds deeply impressive — inflammation this and telomere that — but at the end of the day, none of it really matters,” Lurie said. “You’ve got to show clinical benefit in humans: Does it work?”

Peptide promoters lean on anecdotes, often without verifiable numbers. In a podcast recorded at the White House, the MAHA influencer Brecka said: “Twenty million people have been prescribed these things without adverse events.” His guest on the episode, Brigham Buhler — who is the co-author of The Peptide Revolution and owner of a compounding pharmacy that sells peptides and a clinic, Ways2Well, that prescribes them — told Brecka that none of its 75,000-plus patients had reported adverse events from peptides.

Buhler cited even higher numbers in the movie MAHA Uncensored, a documentary featuring Kennedy and other leaders of the MAHA movement and that bears the MAHA trademark. In the segment on peptides, Buhler said: “Having treated literally hundreds of thousands of people through our compounding pharmacy, we’ve never had a major adverse event.”

Topol asks why those boasting success haven’t conducted clinical studies. “If influencers and companies really believe these peptides are helping people,” Topol said, “then they should put their profits back into rigorous research.”

Chris Woodward, a spokesperson for Brecka and his company, the Ultimate Human, said in an email that the health and wellness issues discussed on Brecka’s podcast do not constitute medical advice. “Mr. Brecka consistently advises his audience to consult a licensed physician,” Woodward wrote. Buhler did not respond to requests for comment.

Not all anecdotes are rosy. At an antiaging conference last summer in Las Vegas, two women were rushed to the hospital and intubated after being injected with experimental peptides and vitamins, according to citations that Nevada’s state pharmacy board issued against the doctor running the booth and his colleagues for prescribing and administering drugs without a state medical license.

An FDA database for adverse events contains concerning reports. Although the database can’t prove that a drug, vaccine, or medical device caused harm — the reports are brief, unverified, and voluntary — it signals issues worth exploring. A 36-year-old woman was hospitalized in December after taking the experimental peptide BPC-157 for weight control and a skin disorder, for example, and a 48-year-old man was hospitalized with a “life-threatening” condition after taking the peptide.

FDA scientists presented some of these reports at the July meeting and flagged worrisome outcomes in animal experiments, such as a 2020 study revealing signs of liver toxicity in rats and dogs injected with BPC-157.

Brian Lee, a liver disease specialist at the University of Southern California, was among the panel’s minority who voted against easing restrictions. Without clinical studies, he said, afflictions that take time to develop, like liver damage and cancer, might not be spotted for years: “I think this endorsement can be potentially harmful, and I cannot in good conscience vote ‘yes.’”

The panel’s newcomers disagreed. “I do not believe the FDA made a good case on issues with safety with BPC,” said Kris Wusterhausen, founder of an antiaging company in Texas, the Resurge Clinic, which sells a BPC-157 product for $149.

“Once you’ve seen the effects of BPC,” he said, “you can’t unsee it.”

Awaiting Trial

Deepak Srivastava, president of the Gladstone Institutes in San Francisco, designed a clinical trial two decades ago to see if a peptide he studies, TB-4, could repair tissue after a heart attack. Before enrollment, people volunteering for the study would be screened for early signs of cancer because TB-4 triggers vessel growth and cell migration, which might exacerbate malignant growths. He worries about the FDA panel’s vote to ease restrictions on a derivative of TB-4, before such trials have been completed, saying, “You need to have a healthy respect for the fact that drugs can be harmful.”

Pinchas Cohen, a peptide researcher at the University of Southern California, was less cautious, saying the FDA buzz might drive investors to fund trials. He’s seeking support to bring a peptide his lab identified, MOTS-c, to market. It’s “un-ideal” for people to take unproven drugs, Cohen said, but that’s what’s happening: “The world is changing and people like me need to accept that this is the new reality and find ways to make it as safe as possible.”

In the meantime, people like Meetze resort to podcasts and online forums for advice. His symptoms faded after a year, but he still had spells of feeling “zero emotions.”

Peptide users describe this condition as anhedonia. It’s come up on Huberman’s podcasts.

Huberman occasionally mentions other potential peptide risks, like cancer, sprinkling them into advice on how to take them. Take a 2024 episode with 1.2 million views: “I do not think that BPC-157 is not without its quote-unquote ‘side effects,’” Huberman says. “If you’re going to go down this path of taking BPC-157, I would encourage you to take the minimal effective dose, to not simply do it every day, and certainly to not do it continuously, and of course to monitor your other health metrics for anything that could potentially resemble cancer or tumor growth, because obviously stimulating angiogenesis for wound repair sounds like a great thing, recovering and being able to do your workouts or play your sport, or move about more comfortably, of course, a wonderfully attractive thing to do.”

“Isn’t that what we all want? But obviously not with the trade-off of growing a tumor,” he said, before interrupting the discussion to advertise a supplement company sponsoring the show.

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.