Unapproved peptides gain popularity despite safety concerns
More Americans are self-injecting peptides that have not been approved for human use, drawn by claims they can build muscle, rejuvenate skin or extend life. The trend has been amplified by influencers, celebrities and allies of Health Secretary Robert F. Kennedy Jr., and comes amid broader public interest in novel weight‑loss drugs and longevity treatments.
What are these peptides?
Peptides are short chains of amino acids that act as building blocks for proteins and help regulate hormones involved in growth, metabolism and healing. Some peptides are approved medicines — for example, insulin for diabetes and growth hormone for certain pediatric conditions — but many products promoted online have never been tested in rigorous human clinical trials.
Who's promoting them?
Influencers, wellness clinics and a handful of high‑profile figures have enthusiastically promoted peptides. Supporters include self‑described “biohackers” and longevity advisers who sell peptide vials, nasal sprays and patches priced from hundreds of dollars per dose. Public endorsements from celebrities and mentions on popular podcasts have helped normalize self‑administration.
Regulatory and safety concerns
Many of the peptides in circulation are labeled "research use only" — language that lawyers say is often used to try to evade Food and Drug Administration (FDA) oversight. The FDA does not regulate chemicals not marketed for human use, which has led to a grey market of products manufactured either by compounding pharmacies or overseas chemical suppliers.
Experts warn that research‑grade peptides may contain impurities, leftover chemicals from manufacturing, or incomplete peptide fragments. Doses being used by consumers can be far higher than levels naturally found in the body, increasing the risk of allergic reactions and other harms. Some peptides, such as BPC‑157 and TB‑500, have been banned by international sports authorities as doping substances.
“None of them are proven,” said Dr. Eric Topol, director of the 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.”
FDA response and legal battles
For years the FDA has sought to rein in risky peptide marketing, issuing warning letters to clinics and adding dozens of peptides to a list that should not be compounded by specialty pharmacies. Pharmacies that violate those restrictions risk fines, litigation or loss of licenses.
Those measures prompted pushback from some compounding pharmacies and wellness advocates, who mounted lawsuits and lobbying campaigns. In some cases the litigation forced the FDA to convene advisory panels to re‑examine the risks; independent advisers have generally agreed with the agency that many of these peptides are too risky for compounding.
Policy shift risks
Recent personnel changes at the FDA and public statements by influential figures have raised the possibility of looser enforcement. Critics fear that removing experts from advisory panels or changing enforcement priorities could allow previously barred peptides to reenter the market more widely.
What clinicians recommend
Doctors urge patients to treat these products with caution. Clinicians recommend asking a simple question before considering any peptide therapy: Is this proven safe in long‑term human studies? Until high‑quality trials demonstrate safety and efficacy, many health professionals advise against self‑injecting unapproved substances obtained outside regulated pharmaceutical channels.
Bottom line: Interest in peptides reflects a broader appetite for quick fixes and alternative health solutions, but experts warn the science is incomplete, products may be contaminated or mislabeled, and long‑term harms are unknown. Consumers should consult qualified health professionals and rely on treatments with proven safety profiles.
AP video journalist Javier Arciga contributed reporting from San Diego. The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute and the Robert Wood Johnson Foundation; AP is solely responsible for the content.
