WASHINGTON (AP) — More Americans are injecting themselves with unapproved chemicals that are pitched as ways to build muscle, rejuvenate skin and extend life, the latest example of the nation’s fascination with alternative therapies and wellness hacks.
Behind the trend is the surging popularity of GLP-1 weight loss medications, a class of so-called peptides approved to help users quickly shed pounds.
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Health and Human Services Secretary Robert F. Kennedy, Jr., arrives on stage at the inaugural Make America Healthy Again summit at the Waldorf Astoria, Wednesday, Nov. 12, 2025, in Washington. (AP Photo/Rod Lamkey, Jr.)
Health and Human Services Secretary Robert F. Kennedy, Jr., speaks at the inaugural Make America Healthy Again Summit at the Waldorf Astoria Hotel, Wednesday, Nov. 12, 2025, in Washington. (AP Photo/Rod Lamkey, Jr.)
In this image taken from video, an IV infusion is administered at Pure Alchemy Wellness, Tuesday, Nov. 11, 2025, in Chula Vista, Calif. (AP Photo/Javier Arciga)
Andrea Steinbrenner receives an IV infusion at Pure Alchemy Wellness, Tuesday, Nov. 11, 2025, in Chula Vista, Calif. (AP Photo/Javier Arciga)
But the peptides being promoted by influencers, celebrities and wellness gurus are different: Many have never been approved for human use and much of their purported evidence comes from studies in rats and other animals. Several peptides, such as BPC-157 and TB-500, are banned by international sports authorities as doping substances.
“None of them are proven,” said Dr. Eric Topol, a research methods expert and director of Scripps Research Translational Institute. “None of them have gone through what would be considered adequate clinical trials, but nonetheless many people are taking these. It’s actually quite extraordinary.”
Those who’ve highlighted peptides’ benefits include Health Secretary Robert F. Kennedy Jr., who has built a national following among Americans who are deeply skeptical of health experts, pharmaceutical companies and traditional medicine.
For years, the Food and Drug Administration has been trying to crack down on the space, sending warning letters to clinics that promote the products and adding more than two dozen peptides to a list of ingredients that should not be made by specialty pharmacies that often custom mix the formulations.
That approach may be coming to an end.
Kennedy has vowed to end "FDA’s war” on peptides and other alternative treatments that are embraced by many in his Make America Healthy Again movement.
Some of Kennedy’s friends and associates are among the biggest proponents, including self-described “biohacker” and “longevity expert” Gary Brecka, who sells peptide injectables, patches and nasal sprays through his website for $350 to $600 each.
In a May appearance on Brecka’s podcast, Kennedy again promised to “end the war at FDA” on peptides, stem cells, psychedelics and other fringe therapies.
“Music to my ears,” Brecka replied.
Brecka declined to be interviewed for this story.
Peptides are essentially the building blocks of more complex proteins. Inside the human body, peptides trigger hormones needed for growth, metabolism and healing.
The FDA has approved a number of peptides as medications, including insulin for diabetics who don't naturally produce it and human growth hormone for children with developmental disorders caused by low levels of the hormone.
But many other peptides promoted online have never been approved, making them technically illegal to market as drugs. Under current FDA guidance these peptides also are ineligible for compounding — the process in which pharmacies mix made-to-order medications for patients.
That hasn’t stopped celebrities and influencers from touting them.
Joe Rogan, for example, has repeatedly praised BPC-157, a peptide derived from acids found in the gut.
“I had tendonitis in my elbow, I started using BPC-157 and it was gone in two weeks,” Rogan told his podcast audience last year.
He is among the celebrity clients listed on the website of Ways 2 Well, a Texas-based company that offers peptides, stem cells, vitamin infusions and other alternative treatments.
It’s all part of “the circus of unproven, expensive and possibly dangerous” offerings promoted by wellness and longevity clinics, said Topol, who has written about the industry.
For $99, Ways 2 Well offers a “peptide consult" with a physician, after which the company ships the peptide vials along with a “full kit with dosing, instructions and syringes,” according to its website.
Company founder Brigham Buhler is a former pharmaceutical sales rep. He did not respond to requests for comment.
Andrea Steinbrenner, a consulting executive, said she became intrigued by peptides after hearing about their benefits for “longevity, repair, anti-aging and energy,” from an acquaintance who runs a clinic outside of San Diego.
Steinbrenner and her husband now receive monthly infusions at the clinic, in addition to daily supplements.
“I think peptides are popular right now because we are the aging generation and we are looking for alternatives to modern day medicine,” she said. “I absolutely believe in modern day, western medicine— it’s necessary. But there’s a lot of other things in the universe that the earth supplies.”
Peptide proponents often suggest their products are safe because they are based on substances found in the body.
“Unlike synthetic pharmaceuticals, peptides are naturally recognized by your body,” Brecka told his more than 2 million Instagram followers in February.
Critics point out that the peptides for sale are often imperfect synthetics and are taken at doses much higher than any peptides in the body, raising the risk of allergic reactions and other harms.
Brecka sells more than a half-dozen peptides, including ipamorelin and CJC-1295 — both of which the FDA has flagged for serious safety risks.
Like other peptides sold on Brecka’s website, the ipamorelin vials carry the labeling: “research use only.”
The “research use” language is pervasive across the peptide space, even in forums where users trade tips for buying, dosing and “stacking” different drug combinations.
One Facebook group instructs members what words to avoid: “instead of ‘taking’ you are ’researching' peptides.”
Lawyers who work in the field say the language is an attempt to skirt FDA regulations. The agency does not oversee chemicals that aren’t intended for human use.
It’s often unclear whether such peptides are being produced in the U.S. by pharmacies and mislabeled for research, or whether they are being purchased from chemical manufacturers, many located in China and not subject to FDA drug quality standards.
“Research-grade peptides are going to have junk in them,” said Paul Knoepfler, a cellular biologist at the University of California Davis. “They’re going to have chemicals used in the purification process and fragments of peptides that you don’t want.”
On platforms like TikTok, companies in China and other countries offer to ship dozens of peptide varieties to the U.S. for as little as $5 a vial.
“What’s actually in there?” Knoepfler said. “If someone injects it under their skin, what are they getting?"
During the COVID-19 pandemic, the FDA issued over a half-dozen warning letters to businesses promoting peptides with “immune-boosting powers."
Then in 2023, the agency added nearly 20 peptides to a list of substances that should not be compounded due to safety risks. Pharmacies violating the measure risk fines, legal action or potential loss of their state licenses.
That triggered pushback from wellness entrepreneurs and compounding pharmacies, including lawsuits.
One coalition, Save Peptides, warned its followers: “Our basic human rights to access alternative medical care using regenerative peptides is being stripped away by the FDA.”
A lawsuit brought by a large compounding pharmacy alleged that regulators had skipped legally required steps when adding peptides to FDA's list of high-risk substances. The litigation forced the agency to backtrack, and the FDA late last year agreed to convene two public meetings of outside advisers to review several peptides flagged for safety risks.
In each case, the experts agreed with the FDA, voting that the substances were too risky to be compounded.
Some in the industry disagree.
“Physicians should have every available arrow in the quiver to treat illness and, because of the FDA’s inaction, they don’t,” said Lee Rosebush, who helped bring the lawsuit against FDA and represents a group of large compounding pharmacies.
The FDA, under Kennedy's authority, recently removed a number of experts from the compounding advisory panel.
That could pave the way for appointing more peptide-friendly experts who might vote to allow some of the drugs that the FDA previously barred. Alternately, the FDA could simply release a list of peptides and tell pharmacies and clinics that the agency won't enforce bans against them.
For now, doctors say they are fielding more questions from patients excited about peptides and seeking prescriptions.
“Patients should be really asking their health care professionals: Are these medications safe long term?” says Dr. Anita Gupta of the Johns Hopkins School of Medicine, who served on FDA’s compounding committee until earlier this year. “That’s the question I would ask if I was a patient.”
AP video journalist Javier Arciga contributed to this story from San Diego.
The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Department of Science Education and the Robert Wood Johnson Foundation. The AP is solely responsible for all content.
Health and Human Services Secretary Robert F. Kennedy, Jr., arrives on stage at the inaugural Make America Healthy Again summit at the Waldorf Astoria, Wednesday, Nov. 12, 2025, in Washington. (AP Photo/Rod Lamkey, Jr.)
Health and Human Services Secretary Robert F. Kennedy, Jr., speaks at the inaugural Make America Healthy Again Summit at the Waldorf Astoria Hotel, Wednesday, Nov. 12, 2025, in Washington. (AP Photo/Rod Lamkey, Jr.)
In this image taken from video, an IV infusion is administered at Pure Alchemy Wellness, Tuesday, Nov. 11, 2025, in Chula Vista, Calif. (AP Photo/Javier Arciga)
Andrea Steinbrenner receives an IV infusion at Pure Alchemy Wellness, Tuesday, Nov. 11, 2025, in Chula Vista, Calif. (AP Photo/Javier Arciga)
