Fact vs. fiction: Doctors share whether peptides are safe and effective

From YouTube influencers to Reddit threads, the health and wellness side of the internet is full of talk about peptides.

The term refers to a class of chemical compounds made up of short chains of amino acids. In the wellness market, synthetic peptides are often sold to consumers as injectables, which some health influencers say can bring a wide range of health benefits from muscle recovery and longevity to improved sexual function. Some peptides, including GLP-1 drugs commonly used for weight loss or diabetes, are heavily researched and federally approved for medical use. Many other forms of peptides are not.

Yet even some lightly researched peptides may be on their way to pharmacy shelves. The Department of Health and Human Services is reportedly planning to allow specialty pharmacies to compound certain synthetic peptides that have the support of Health Secretary Robert F. Kennedy Jr., who told podcaster Joe Rogan that he is a "big fan" of the injectables in a February 2026 interview. As reported, the move would be an interim access policy covering some specific peptides not currently approved by the U.S. Food and Drug Administration.

Such a move would be controversial from a regulatory point of view: Multiple peptides, including one of the compounds reportedly included in the health department's proposal, appear on an FDA list of injectables that "may present significant safety risks." That compound, known as BPC-157, has shown potential anti-inflammatory effects in some animal and lab studies but has not yet been subject to large-scale human testing for safety or effectiveness.

"There are a few reasons why, but one of the main ones is the absence of evidence," including robust human studies on safety and effectiveness, says Dr. Caleb Alexander, a professor of epidemiology and medicine at the Johns Hopkins Bloomberg School of Public Health.

Yet consumer interest and regulatory momentum for peptides are growing. So here's what you need to know about peptides, from why they're the subject of such conversation to whether or not they're safe or effective to use.

What are peptides?

Peptides are "kind of like the building blocks of proteins," says Dr. Alison Dempsey, a dermatologist at the Weill Cornell Medicine and NewYork-Presbyterian Hospital.

Several different types of peptides are naturally found in the body, like insulin and endorphins. Peptides can also be synthesized in labs, according to Harvard Health Publishing. GLP-1s, like Ozempic, are FDA-approved synthetic peptides, Dempsey says.

Injectable variations of synthetic peptides that haven't been approved by the FDA — such as BPC-157 and GHK-Cu, the latter of which has been marketed as a potential anti-aging drug — are the peptides that are making headlines at the moment, says Dr. Pieter Cohen, an associate professor at Harvard Medical School and internist at Cambridge Health Alliance.

Why are peptides gaining popularity among wellness influencers and some other consumers?

One likely factor behind synthetic peptides gaining more attention has been the success of drugs like Ozempic at addressing health concerns such as obesity and diabetes, according to Cohen. "That probably opened up [the idea that] there must be this magical world of these other peptides that we can have access to, that will do these sort of similar magical things in other areas," he says.

However, Cohen and other health experts have their concerns. After all, a compound's status as a peptide "doesn't mean it's close to Ozempic in any way, shape or form ... in terms of both its chemical structure or its effects on the human body," says Cohen.

Synthetic peptides advertised on social media and sold on the so-called gray market — often produced by overseas sellers and sold to U.S. consumers outside the normal American drug regulatory system — come with marketing claims such as boosting longevity, improving sleep quality, strengthening the immune system and even enhancing skin health and sexual function, according to Alexander.

Particularly among the people who consider GLP-1s a form of miracle drug, consumers may simply want to believe that the weight loss medicine's chemical cousins could have similar effects on other elements of human health. "Unfortunately, when it comes to peptides marketing, word of mouth has strongly surpassed where we are with any type of research," Dempsey says.

What do health experts recommend for consumers?

The health experts who spoke with CNBC Make It recommend against using any injectable peptides that aren't approved by the FDA, especially if you're unsure where or how they were produced. Always consult with a medical professional before making any major changes that can affect your health.

"My recommendation is not to use any of the novel, unstudied injectable peptides because we simply do not know if they work. And if they do work, if they're safe," Cohen says. When buying peptides on the gray market, you can receive entirely different compounds or doses, and some may be contaminated with bacteria or other concerning materials, he says.

"There's concerns both about the potential risks, but also about the unclear level of benefit from these products," Alexander says.

"We have a great regulatory system governing prescription drugs in the United States," Alexander adds. "For advocates of these products that really believe in them, I hope that they'll put their money where their mouth is, and do the studies that are necessary so that we can understand the true safety and effectiveness of the products."