FDA Scientists Find Little Evidence for Seven Peptides Kennedy Backs for Compounding

FDA staff reviewers have told their own advisory panel that there is scant human evidence to justify letting compounding pharmacies manufacture seven widely marketed peptides, a finding that puts career scientists directly at odds with Health and Human Services Secretary Robert F. Kennedy Jr., who has publicly called himself a "big fan" of the compounds.

The assessment, outlined in briefing documents the agency posted Monday, comes ahead of a two-day meeting of the FDA's Pharmacy Compounding Advisory Committee scheduled for July 23 and 24 in Silver Spring, Maryland. According to a Reuters report reviewed for this story, the panel will decide whether to add the peptides to the list of bulk drug substances permitted for use in compounded medicines.

The seven substances under review are BPC-157, KPV, TB-500, MOTS-c, emideltide (also known as delta sleep-inducing peptide), semax and epitalon. Their proponents have pitched them for uses ranging from wound healing and ulcerative colitis to obesity, osteoporosis and chronic insomnia. But according to reporting by NBC News, FDA scientists found that for TB-500 and KPV, they could not locate any studies in which either substance had been administered to humans at all. For MOTS-c, nominated as a potential treatment for obesity and osteoporosis, no published human studies existed either.

The patient-side stakes are real. Compounded drugs already carry higher risk than FDA-approved products: quality control is variable, oversight is lighter, and the substances involved haven't cleared the evidentiary bar that approved medicines do. As Prism News reported in documents reviewed by this outlet, patients who access these products through compounding pharmacies could be exposed to agents with uncertain benefit-risk profiles and uneven product quality. If access expands through a favorable panel vote, that exposure widens.

The composition of the advisory panel itself has drawn scrutiny. According to Reuters, one panelist runs a clinic that already offers patients peptide therapies for pain relief, muscle growth and longevity. Another, a Tennessee state senator and licensed pharmacist, has a mother in Congress who wrote to Secretary Kennedy last year urging looser FDA restrictions on peptide production. HHS said in a statement that all committee members cleared the same ethics review required of any FDA advisory panel member, and that candidates who couldn't meet existing ethics requirements were removed.

The committee's recommendations are formally non-binding, but the FDA generally follows them, making the two-day session a meaningful signal of where the agency is headed under the current administration.

This isn't the only peptide-adjacent front the FDA is managing. In April 2026, the agency proposed excluding semaglutide, tirzepatide and liraglutide from a separate compounding pathway, saying it found no clinical need for outsourcing facilities to prepare those approved GLP-1 drugs from bulk substances.

For clinicians and patients, the distinction matters: the GLP-1s the agency wants to pull back from compounding have extensive human trial data. The seven peptides heading into next month's hearing largely don't. That gap in the evidence base is exactly what FDA scientists flagged this week, and it's the question the advisory panel will have to answer when it convenes in three weeks.

Sources cited:
- Reuters / U.S. News & World Report (https://www.usnews.com/news/top-news/articles/2026-06-30/fda-staff-question-peptides-backed-by-kennedy-ahead-of-advisory-panel-review)
- Prism News (https://www.prismnews.com/news/fda-staff-question-evidence-for-seven-peptides-setting)
- NBC News (https://www.nbcnews.com/health/health-news/rfk-jr-wants-make-easier-get-peptides-fda-scientists-disagree-rcna352323)
- AJMC (https://www.ajmc.com/view/fda-to-convene-expert-panel-on-expanding-access-to-peptides-amid-safety-regulatory-debate)