Spend enough time in wellness circles, biohacking forums or men's health clinics, and peptides begin to sound less like a class of molecules and more like the new language of the healthy.
Its expanding vocabulary includes obscure-sounding names like GHK-Cu, BPC-157, PT-141 and semax — marketed online as the “beauty peptide,” “Wolverine peptide,” “date-night peptide,” and “focus peptide.” A quick social media search yields videos of animated, AI-generated peptide vials cheerily explaining their benefits and of influencers demonstrating self-injection with hypodermic needles, followed by long comment threads about sourcing. These videos are usually accompanied by disclaimers that the content is “not medical advice” and appeals to moderators not to remove the posts.
Peptides are not new in medicine. The peptide hormone insulin, for example, has been used to treat Type 1 diabetes since its discovery over a century ago. The current craze can be traced back about a decade to members the CrossFit and other workout communities, who began experimenting with peptides as alternatives to anabolic steroids.
Then came the unprecedented success of weight-loss drugs like Ozempic and Wegovy — whose key ingredient mimics the naturally occurring peptide GLP-1 — and the explosion of the “looksmaxxing” movement of the 2020s.
There have also been high-profile endorsements, including from U.S. Department of Health and Human Services Secretary Robert F. Kennedy Jr., who extols peptide use, claiming to have injected some himself and proposing to loosen restrictions on compounding pharmacies’ ability to manufacture them.
This June, staff scientists at the Food and Drug Administration delivered a blow to Kennedy’s proposal, citing a lack of evidence for their efficacy. The evidence is expected to be reviewed again by a second committee later this month, which will make a final recommendation.
What will become of today’s most talked-about molecules?
What is ‘peptide therapy?'
The human body produces thousands of peptides, which are short chains of amino acids and the precursors to proteins. Peptides act as hormones, neurotransmitters and cellular signaling molecules, and many of their functions in the body are still being discovered.
The term “peptide therapy,” however, encompasses a more diverse collection of compounds. A small number of these — including GLP-1 peptides, sermorelin, tesamorelin and thymosin alpha-1 — have undergone extensive clinical testing and received regulatory approval for specific medical indications. A larger number remain investigational compounds supported by limited clinical data.
Because peptides lack approval, some users turn to the “gray market,” seeking peptides labeled as “research chemicals” from foreign manufacturers.
The rapid expansion of the peptide marketplace tends to blur distinctions, placing FDA-approved medications, experimental therapeutics and a holistic medicine-inspired treatment philosophy under a common conceptual umbrella.
“It’s not really a drug in the way we looked at drugs in the past,” explained Shawn Gab, manager at the peptide and testosterone replacement therapy clinic Gameday Men’s Health in Metairie. “[A peptide] is basically an amino acid telling your body how to … correct a mistake — it's just sending that signal to do it — whereas most medications are blocking pathways.”
In some fitness communities, the word “drug” has a negative connotation, stemming from an association with illegal performance-enhancing anabolic steroids.
Peptides are seen as a natural alternative, even though commercially available peptide products may differ substantially from naturally occurring molecules: Some must be chemically modified in a lab to increase their stability in the body, and some are mixed with other compounds or contain impurities.
Increasing interest in medical autonomy and distrust of medical authority in the post-COVID years may also explain the cultural shift toward “natural” medicines and supplements, said Mariana Craciun, a medical sociologist at Tulane University.
The turn toward natural medicine reinforces an inclination to reject medical expertise, she said. “We want to be the ones who are the intermediaries between this expert knowledge and our bodies, rather than letting a doctor be that intermediary.”
Evidence, regulation and clinical practice
For researchers like Dr. Frank Greenway, chief medical officer of the Clinical Trials Unit at Pennington Biomedical Research Center in Baton Rouge, the central issue is not whether a compound is natural but whether its risks and benefits have been rigorously evaluated.
Dr. Frank Greenway, Chief Medical Officer of the Clinical Trials Unit at Pennington Biomedical Research Center.
Photo provided by Pennington Biomedical Research Center
Greenway’s own research focuses on characterizing the pharmacological properties of everyday foods and herbal supplements, with the goal of discovering novel obesity treatments.
“I [went] into medicine because I really want to help people … and when I do something, I don't hurt them more than I help,” Greenway said. “When you go by people who are influencers or people who don't really have medical knowledge … you're certainly not assured that the risks are outweighed by the benefits.”
Perhaps the most researched peptide is MOTS-c, a so-called “exercise mimetic” that regulates metabolism. After promising studies in animal models, it was taken to a Phase 1 clinical trial, but was ultimately nominated to the for its potential to trigger immune system reactions. It has since been withdrawn from the list, pending a formal safety review.
Other popular peptides, such as BPC-157, have even sparser clinical evidence to date. Despite many reported benefits related to speeding up muscle repair, healing ulcers, regenerating nerves and slowing neurodegenerative disease in cell and animal models, no controlled human trial of the peptide has been published in the 30-plus years since its discovery.
Even among supporters of peptide therapies, concerns about sourcing and quality control are common. Dr. Thomas Bond, an orthopedist who has incorporated peptides into his regenerative medicine practice in Lafayette for more than a decade, recalled treating patients hospitalized after obtaining peptide drugs online.
“I had three hospital admissions for acute pancreatitis for people that got stuff online,” he said.
Dr. Thomas Bond, an orthopedist who has incorporated peptides into his regenerative medicine practice in Lafayette for more than a decade.
Provided photo from Bond Medical Center
There have been a number of reports of people being harmed after taking unknown peptides. At the Revolution Against Aging and Death Festival last year, two women who received injections at a conference booth with swollen tongues, elevated heart rates and trouble breathing, and had to be intubated.
Bond acknowledged the reality of medical self-experimentation but urged peptide users to consult with a medical professional to ensure they would not have contraindications.
“I am a big fan of peptides, but peptides done the right way — as an adjunct to a medical or surgical procedure,” Bond said. “They're not the panacea hype that is all over social media … it's really even beyond irresponsible in my opinion. I think it's reckless and dangerous.”
Looking ahead
The second upcoming FDA advisory committee review this month will consider whether compounding pharmacies should be permitted to manufacture seven peptide compounds.
Among those under review are BPC-157, which has been investigated for inflammatory bowel disease and tissue repair; TB-500, promoted for wound healing; MOTS-c, studied experimentally for metabolic disorders; KPV for inflammatory conditions; semax for neurological disorders; emideltide for opioid withdrawal and insomnia; and epitalon for sleep-related indications. The committee's recommendations could influence how readily these compounds remain available outside the traditional pharmaceutical approval pathway.
Half the committee’s members have professional ties to clinics, pharmacies or companies involved in peptide therapies. They include executives from wellness providers, physicians who prescribe peptide-based treatments and pharmacists with experience in compounding.
“All committee members underwent the same ethics review and vetting process required of all FDA advisory committee members. Candidates that could not meet existing ethics requirements were removed from consideration,” an HHS spokesperson said.