A US Food and Drug Administration (FDA) advisory panel voted to loosen restrictions on controversial peptides that have become popular online but have not been well researched for use in humans.

The panel voted narrowly to allow specialty pharmacies to produce drugs such as BPC-157, TB-500 and KPV, a major regulatory hurdle to making them available by prescription.

Peptides are small proteins that our bodies normally produce and have long been used to treat medical conditions, including diabetes.

But unregulated injectable peptides have exploded in the online wellness community, including among many young influencers, since GLP-1 (weight loss drugs) became mainstream.

The FDA does not have to follow the panel’s recommendations, but it often does.

Health Secretary Robert F. Kennedy has described himself as a “big fan” of the drugs and previously promised to ease restrictions on them after the Biden administration clamped down on the growing industry.

Peptides are short chains of amino acids or small proteins that our body produces naturally. They act as messengers, telling our cells what to do and play vital roles in the health of our skin, our immune system and helping to control our hormones.

Online influencers have been marketing peptides in “stacks” for unproven uses, claiming that they can be used as a quick way to look younger, help you heal, and improve your skin.

They have become popular among teenagers on TikTok, especially boys, due to unproven claims that certain peptides can help build muscle mass and improve the body, with some online using phrases such as “biohacking” and “looksmaxxing” to describe the trend.

Health experts have warned against the use of these medications, citing the lack of human clinical trials and the unknown long-term effects of the substances.

BPC-157 is one of the most popular peptides among wellness influencers.

It is made from stomach protein and is marketed online as good for gut health, tissue repair, and treating inflammation.

Its potential to help with muscle healing has been studied in animals.

The United States Anti-Doping Agency (ADA) states that because it has not been extensively studied in humans, “no one knows if there is a safe dosage or if there is any way to safely use this compound to treat specific medical conditions.”

The peptide is banned for use in sports and is considered a banned substance by the World Anti-Doping Agency.

KPV is also touted as good for gut health and tissue repair. including skin damage, such as acne, and to regulate the immune system.

Both have been in a gray area when it comes to regulation. They are not illegal to buy or possess (and are widely available online), but they are not approved for human use, so they are not subject to the quality controls that govern pharmaceutical manufacturing.

Panel member Elizabeth Rebello, a pharmacist and anesthesiologist, told the committee she had voted no to BPC-157 “due to a lack of efficacy data” and “safety concerns,” the Reuters news agency reported.

Those who voted in favor reportedly cited “the common good” and “medical freedom” as reasons for their decisions.

Several people who work in clinics or companies that sell peptides are on the panel, which will continue deliberating on Friday.

BPC-157 and KPV are among seven peptides that the panel is considering removing restrictions and allowing compounding pharmacies, which mix drugs that are not available from standard drug manufacturers, to produce.

The peptide restrictions were introduced during the Biden administration, when FDA officials found the drugs did not meet safety requirements. Kennedy has worked to reverse those restrictions.