A divided Food and Drug Administration panel handed a significant victory to Health Secretary Robert F. Kennedy Jr.’s push to promote peptides, voting Thursday to recommend that certain pharmacies be allowed to produce four of the controversial wellness products despite FDA researchers’ calls for caution.

The Pharmacy Compounding Advisory Committee voted to recommend loosening regulations on BPC-157, KPV, TB 500 and MOTS-c, which are among the seven peptides the committee is reviewing across a two-day meeting this week.

The panelists - including members whom ethics and medical experts have accused of having conflicts of interest because of their links to peptide-related businesses and clinics - appeared divided throughout the day as they heard accounts from physicians of successful peptide treatments, arguments about the dangers of an unregulated peptide market and repeated warnings from FDA scientists that there is not enough data to support the peptides’ safety and efficacy.

Peptides are chains of amino acids that perform a range of bodily functions. Some are approved by the FDA, such as insulin and GLP-1 drugs. Many others that have not gone through rigorous clinical trials are being marketed as health and wellness products and can be purchased online, often as “research chemicals,” on a gray market.

After the first vote Thursday morning in favor of BPC-157, applause broke out at the FDA’s White Oak Campus in Silver Spring, Maryland, where advocates for peptides had packed the committee meeting room.

“Today was a huge step for patients and providers in making sure they have medical freedom and safe access to the drugs they need,” said Lee Rosebush, the chairman of the American Academy of Peptide Medicine.

The votes could be the first step toward making the peptides vastly more accessible for Americans. If the FDA decides to allow compounding pharmacies, which produce specialized medicines, to make the peptides, physicians would be able to prescribe them. People would probably also be able to purchase them through telehealth services, which sell many prescription drugs.

Votes on three other peptides are expected Friday. The panel’s decisions aren’t final, and the FDA will ultimately make its own ruling, though it often follows the advice of its committees.

The decisions Thursday are not “a green light to compound with these peptides,” Ilisa Bernstein, a former deputy director of the FDA’s drug compliance office, wrote to The Washington Post. “FDA must keep their eye on the science, data, and patient safety as they consider their options and next steps.”

The peptides the committee voted on Thursday have a range of proposed uses. BPC-157 was proposed to treat ulcerative colitis; Semax to treat conditions including migraines and trigeminal neuralgia, a chronic pain disorder; and KPV and TB 500 to promote wound healing.

Proponents who spoke at the meeting said the peptides are already popular with many Americans and are marketed heavily online. Some influencers tout BPC-157 and TB 500, when taken together, as a “Wolverine Stack” that accelerates healing and reduces inflammation.

Experts have warned that peptides purchased online often contain dangerous impurities, or can be different chemicals altogether. Advocates for the peptides said that allowing pharmacies to produce the peptides, and doctors to prescribe them, would help patients use them more safely.

“As a physician, I have to make sure that I’m keeping patients as safe as possible,” said Haleem Mohammed, the chief medical officer of a health company that sells peptides and a committee member who voted for the peptides. “When I look at something like saying no to (the peptides) and pushing it to the gray market, am I doing greater harm?”

FDA scientists who presented reports on the peptides Thursday said they did not base their evaluations on concerns about the gray market. They said there was insufficient data on the efficacy and safety of the peptides and weighed against recommending them, adding that FDA-approved treatments exist for the conditions the peptides were proposed to treat.

FDA officials at the meeting also said that the peptides are not well-characterized, which means they are described inconsistently or unscientifically and their names can refer to a variety of different formulations with different attributes and potential safety risks.

“I haven’t been on an advisory panel (before) where I didn’t know what it was we were voting on,” said Josh Mailman, president of the Neuroendocrine Tumor Research Foundation and a committee member who voted against the peptides.

The committee members largely voted consistently. Each peptide was passed by a tight margin; 8-6 for BPC-157, TB 500 and KPV and 7-5 for MOTS-c (some members abstained, and others did not vote on every peptide). Among the majority who voted in favor of recommendations for each of the peptides were some members with ties to peptide-related businesses selected by Health Department officials, which led the FDA to raise conflict of interest concerns, The Post previously reported.

Peter Lurie, president of the nonprofit Center for Science in the Public Interest and a former FDA associate commissioner who testified against BPC-157, wrote to The Post that Kennedy “has made a mockery of the advisory committee process.”

“Predictably, his appointees all voted yes,” Lurie said.

The Department of Health and Human Services did not respond to a request for comment. An FDA spokesman has said committee members “underwent the same ethics review and vetting process required of all FDA advisory committee members.”

The committee will vote on the three remaining peptides on its slate - Emideltide, Epitalon and Semax - on Friday. Its decisions could inform upcoming evaluations of peptides. The panel is scheduled to review five more before the end of February.