A little-known advisory group to the US Food and Drug Administration will meet this week to mull over whether to ease restrictions on certain peptides. The injectables are popular among wellness influencers and some doctors, who say they improve muscle recovery, reduce inflammation, promote longevity or simply boost your overall health.

The meeting offers an early glimpse into how the second Trump administration’s drug regulators will respond to the rapidly expanding popularity of peptides that have not been FDA-approved.

The FDA’s Pharmacy Compounding Advisory Committee (PCAC) is scheduled to meet Thursday and Friday to review some of the controversial, popular peptide injections and discuss whether compounding pharmacies should be able to dispense them.

Previous FDA panels have largely been composed of academics and researchers. In contrast, under the second Trump administration, the current committee is made up mainly of health professionals who prescribe, produce or promote peptides.

US Health and Human Services Secretary Robert F. Kennedy Jr. has said he’s “a big fan of peptides” and has used them himself. He’s also said he hopes to relax restrictions around them but has been faced with some resistance within the FDA, which previously determined that some peptides lack sufficient safety data.

This week’s advisory committee meeting represents a pivotal moment in determining whether some of these peptides move closer to mainstream medical practice or remain largely outside it.

Over the course of the two-day meeting, the committee will review seven peptides that have been nominated for inclusion on the FDA’s 503A Bulks List, a list of ingredients that compounding pharmacies may use to prepare customized medications for people under specific legal conditions.

In briefing documents for the meeting, the FDA’s experts say there is a lack of evidence on effectiveness and safety to justify letting pharmacies make the peptides that the panel will review. Across the board, they propose not adding the peptides to the 503A Bulks List.

Although the committee’s recommendations often carry significant weight in the FDA’s decision-making, they are advisory rather than binding. It’s ultimately up to the agency to decide whether to follow the recommendations.

What are peptides?

Peptides are short chains of amino acids, the building blocks of proteins. Some have become important prescription medicines. Insulin, for example, is a peptide, as are widely used GLP-1 medications for diabetes and obesity such as Ozempic and Wegovy. But the peptides now going before the committee are different; they are not FDA-approved.

Even though insulin was the first therapeutic peptide, synthesized in the 1920s, some more recent peptides that are used for anti-aging, wound healing or muscle recovery are still considered to be in their infancy when it comes to research data.

GLP-1 injection medications are among some of the most popular and widely used FDA-approved peptides. Michael Siluk/UCG/Universal Images Group/Getty Images

Some experts have raised concerns about the safety of using emerging peptides that are still considered experimental. Often, they might have labels that say “research use only” or “not for human consumption.” Many people have accessed these peptides online, sometimes from unknown sources, without ever consulting a doctor. And most peptides are administrated by injection.

Supporters of peptides argue that allowing FDA-regulated compounding pharmacies to prepare these medications with a prescription would provide a safer alternative to ordering products online from unregulated internet vendors.

Critics counter that moving the compounds into legitimate pharmacies could create the appearance that they have been proved safe and effective when, in many cases, data from robust clinical trials remains limited. That tension lies at the heart of the upcoming meeting.

Which peptides are under review?

The peptides under consideration this week are:

BPC-157, proposed for treating ulcerative colitis

KPV for wound healing and inflammatory conditions

TB-500 for wound healing

MOTs-C for obesity and osteoporosis

Emideltide for opioid withdrawal, chronic insomnia and narcolepsy

Semax for certain neurological disorders

Epitalon for insomnia

The FDA advisory committee “will be determining whether or not it will allow access to these substances through legitimate state-licensed compounding pharmacies,” said Scott Brunner, chief executive officer of the Alliance for Pharmacy Compounding, who sent a public letter to the committee in support of adding peptides to the list.

However, he added that since many of these experimental peptides don’t have the same robust catalog of clinical trial data as FDA-approved medications, evaluating them for the 503A Bulks List may prove challenging for the committee and the agency.

“The committee usually looks at research clinical trials, and if there’s supporting research clinical trial data, there’ll be a recommendation that they be added to a list of drugs that compounding pharmacies can prepare. That data just doesn’t exist for most of these peptides,” Brunner said. “And so FDA is going to need to use a different lens.”

Unlike FDA approval of a new drug, which requires years of clinical trials demonstrating safety and effectiveness, placement on the 503A Bulks List answers a different regulatory question. It is evaluating whether a drug meets certain criteria, allowing pharmacists to compound it from bulk ingredients for patients with valid prescriptions.

“Essentially, what that would do is it would create a lawful pathway for compounding pharmacies to be able to make products containing these ingredients and dispense them to patients,” said Jesse Dresser, a partner in the law firm Frier Levitt’s Life Sciences Department and head of the firm’s Pharmacy Practice Group.

That means, “if you’re going to get these products, you have to be seen by a physician, you have to have a prescription written, and then you have to go get it from a licensed 503A compounding pharmacy,” Dresser said. “And so it remains to be seen what ultimately happens at this meeting.”

How safe are peptides?

Three years ago, the FDA determined that certain peptides should not be compounded, citing significant safety concerns, including the risk of life-threatening allergic reactions. This week’s meeting revisits the discussion.

Some experts worry that broader availability to certain peptides through compounding pharmacies could expose larger numbers of patients to therapies whose long-term safety profiles remain unclear.

“We currently don’t know the long-term effects of many of these peptides; what are their toxicities, adverse effects or even their drug interactions. FDA approval – Phase 1, 2 and 3 clinical trials – require companies to perform extensive clinical studies to determine drug safety and efficacy. None of the peptides currently being considered for compounding are FDA approved drugs,” said Edgar Asebey, a life science attorney and partner at the Frier Levitt law firm who heads the FDA Practice Group.

Dr. Castel Santana, regional medical director at 10X Health, a health and wellness company that offers peptides, said that he feels confident that most peptides have “minimal or low” associated risk based on his personal experiences prescribing them. But he warns that taking several peptides all at once could lead to interactions between them.

“The fact is that there are some contradictions to it,” he said.

Santana added that he is “happy” the FDA advisory committee is meeting to discuss peptides.

But not all doctors may agree.

When it comes to the meeting, “I think this is a disaster in the works, because these peptides have no data to support their safety and efficacy,” Dr. Eric Topol, a research methods expert and director of Scripps Research Translational Institute, said in April during a call with reporters hosted by the Harvard T.H. Chan School of Public Health.

Ultimately, some experts say that how safe certain peptides are remains unknown without clinical trial data, and the safety could vary based on the substance.

How are they currently regulated?

FDA-approved peptides are regulated in the same way as other approved drugs. But aside from those that are approved as therapeutic medications, the manufacturing of certain peptides is largely unregulated. Many are not eligible to be dispensed by compounding pharmacies, and experts warn that rising demand is fueling an unregulated online market that could be dangerous.

“Patients are getting what purport to be these substances, or are using drugs that are made with research-grade active ingredients, and I almost expect any day now there’s going to be some serious patient adverse event or a series of patients who are made ill or worse by taking batches of these drugs that were not made to FDA standards or with active ingredients that are not made to FDA standards,” Brunner said.

To combat the risky online market, Brunner said, the Alliance for Pharmacy Compounding hopes that the advisory committee will recommend the peptides for pharmacy compounding, which could create a “safer” pathway for access.

Additionally, “FDA should create a green list of authorized FDA-registered manufacturers of these substances,” Brunner said.

“We would argue that pharmacies should only be able to access the active ingredient from FDA-registered wholesalers. We believe that it is reasonable to require an enhanced disclosure to the patient who may be prescribed one of these drugs that this molecule is not as well-characterized as drugs that would normally be dispensed to patients, and the patient needs to understand that there may be a higher risk profile, and they should only be taken under the care of a physician,” he said. “And we believe there is a place for mandatory serious adverse events reporting related to these substances.”

What could the future look like?

If the FDA ultimately permits compounding some of these peptides, patients may find it easier to get them through licensed compounding pharmacies instead of relying on unregulated sources. Physicians may become more comfortable prescribing them. Compounding pharmacies could see significant new business.

Since there are no FDA-approved versions of these peptides, compounding pharmacies could be the only pathway through which people could access these medications in the future, said Dresser, who has represented a number of compounding pharmacies.

“By the same token, because there is not an FDA-approved version out there, there’s no competition risk. There’s no limitation on their ability to produce any particular formulation,” he said. “It’s really just related to whether or not they can get a prescription from a prescriber.”

The future of regulations around peptides may also somewhat mirror how dietary supplements are currently regulated, suggested Dr. Janet Woodcock, a retired FDA veteran and former principal deputy commissioner.

“Dietary supplements are oral, but they have the same sort of regulatory scheme as the compounded drugs, in the sense that FDA can only intervene in them if they cause harm, as demonstrated,” Woodcock said. “They don’t have to have tests or clinical trials or whatever to show they work, but they can’t be harmful, and they can’t make disease claims.”