FDA scientists flag concerns with peptides, the trendy molecules RFK Jr. supports

Synthetic peptides, often taken by injection, are growing in popularity among patients seeking to optimize health and longevity. Yet FDA scientists point to a dearth of evidence supporting their use. Svitlana Pietukhova/iStockphoto/Getty Images hide caption

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While Health Secretary Robert F. Kennedy Jr. pushes to loosen restrictions on a handful of trendy peptide therapies, scientists who work under him are recommending the opposite.

On Monday, the Food and Drug Administration posted documents outlining concerns about a lack of evidence for the batch of peptides that are set to be considered by an FDA panel in about three weeks.

Peptides are a string of amino acids, smaller than a protein, that are produced naturally by our body. The wildly successful GLP-1 weight loss drugs are examples of synthetic peptides.

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But the peptide therapies being touted online for their wellness and longevity benefits have not undergone large-scale, rigorous clinical trials involving humans.

Those under consideration next month include BPC-157, TB-500 and MOTs-C among others that have grown popular among influencers and some clinicians.

They're typically taken as a subcutaneous injection to help with injuries, muscle recovery, metabolism and more.

In their review of the evidence, FDA scientists flag potential safety concerns and a lack of consistent data.

The Biden administration placed restrictions on these and a handful of other peptides in 2023 — moving them into a category that essentially prohibits compounding pharmacies from making the drugs.

In the years since, peptide users have turned to a grey market , often sourcing the products from sketchy suppliers overseas.

Secretary Kennedy has made no secret of his support for the molecules, saying he has used some of them himself and would like the FDA — which is overseen by the Department of Health and Human Services — to allow compounding pharmacies to again offer the drugs.

The panel selected to review the evidence in July is made up of members who have ties to the peptide industry , including some who work for companies that offer injectable peptides. They are expected to make recommendations on seven peptides during a two-day meeting on July 23 and 24 and then reconvene in February to consider others.

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The panel will review the evidence supporting the use of these peptides for specific indications, including ulcerative colitis, wound healing, obesity, and migraines.

It's unclear how they'll weigh the findings of the career scientists at the FDA who state there's insufficient evidence to support changing the designation for any of the seven peptides under consideration.

Their conclusion echoes what others have found when they've looked at the body of evidence for these therapies.

"Not a day goes by where I don't have a number of patients asking me about peptides," says Dr. Alexander Weber , an orthopedic surgeon and chief of sports medicine at the University of Southern California who has published a review of the evidence, "My stock answer is that we just don't have enough data to support their use."