Doctors warn of risks tied to unregulated peptides gaining popularity for weight loss - WSET

Doctors warn of risks tied to unregulated peptides gaining popularity for weight loss

(WSET) — As interest in weight loss medications and peptide therapies continues to grow, doctors are warning consumers about the risks associated with unregulated peptides that are increasingly being marketed online for weight loss, muscle recovery, injury healing and overall wellness.

Alessandro Schiavone, who has been lifting weights for the past decade, began taking peptides after developing pain in his joints and tendons.

"I've been taking peptides since November," Schiavone said.

He uses two peptides known as BPC-157 and TB-500, a combination often referred to online as the "Wolverine Stack."

"So I take BPC-157 and TB-500 to kind of just help with my tendons, my joints and overall better muscle recovery," Schiavone said.

The nickname comes from claims that the peptides can accelerate healing in muscles, tendons, ligaments and other soft tissues.

Schiavone said he has noticed significant improvements in his recovery since beginning the regimen.

"How have your muscles and tendons felt?" Robertson asked.

"I've told a bunch of my friends this — it feels like when I first started lifting when I was 16 years old. I can go the next day and feel no effects from the lift I did prior," he said. "I really haven't felt any sort of aches and pains in my elbows. I used to get really bad tendonitis in my bicep, and I haven't had that since I started taking it."

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While testimonials like Schiavone's have helped fuel growing interest in peptides, medical experts, like UVA Health Obesity Director Dr. Catherine Varney, caution that many of the products being promoted online have not undergone the rigorous testing required for approval by the U.S. Food and Drug Administration.

"A peptide is a protein molecule that our body naturally makes," said Dr. Varney.

Varney, who has worked in obesity medicine for 16 years, explained that FDA-approved weight loss medications such as Ozempic and Wegovy are synthetic drugs designed to mimic naturally occurring peptides in the body, including insulin and glucagon-like peptide-1, or GLP-1.

Those medications have undergone extensive testing and are regulated by the FDA.

However, Varney said the peptides Schiavone uses are different.

"They can be legally created, but they're unregulated by the FDA," Dr. Varney said. "Those regulations are there for safety, and it takes rigorous testing."

Many of these products are sold online and can cost anywhere from $50 to $300.

Varney said the lack of regulation raises concerns about product quality, safety and effectiveness.

A study conducted in Belgium found that some unregulated peptides sold online contained heavy metals, including arsenic and lead, both of which can be toxic to the human body.

The peptides are typically administered through injections, with some users taking them daily and others using them once or twice a week.

Despite the safety concerns, Varney said she continues to encounter patients who use unregulated peptides.

"Have you seen any adverse side effects?" Robertson asked.

"I have seen adverse side effects," Varney said. "The one that I've seen the most has been an increase in liver function tests, telling me that the liver is being strained by something. It's a direct correlation. When I tell them to go off these medications, the liver function improves. I think that sometimes that's also what the patient needs to see - it's actually harming me."

Varney said many of the products are sold through what is often referred to as the gray market, meaning they are distributed outside official regulatory channels and are frequently labeled "for research use only."

She also pointed to social media marketing as a major driver of consumer interest.

"So you have a wide variety of people promoting these medications, anywhere from personal trainers all the way up to physicians," Varney said. "The problem with these medications is that they've shown some benefits in animal models, but they have not been proven to be effective or safe in humans."

Alex shared that he gets his peptides from a clinic and knows what's in them.

"It's definitely a slippery slope when you start taking things that you don't really know where they're coming from, which is kind of why I steer away from that route," Alex said. "Personally, the stuff that I take is from a compounding pharmacy, and you know they have third-party testing certification, and I can look up the batch number and find the certificate for all the testing, and so I kind of know that the purity level is 100%."

"Even with the risks that have probably been told to you or the risks that you've read about, does the reward outweigh the risks?" Robertson asked.

"Personally don't have any risk with it to be honest with you," Alex said. "I think these have been out for a while now. I mean, maybe not by the FDA, but the FDA is not the be-all end-all with all things healthy."

Dr. Varney sympathized, saying she understands there is a lot of distrust; however, she believes people who are looking to lose weight are being exploited by people marketing these unregulated peptides.

"I understand that we've gone through a really tumultuous time in the last five years, and there's a lot of distrust in the government, in medicine, and doctors from what we did with COVID, but we did the best we knew at the time. I think with obesity, I think that people are so desperate for treatment, and I think they deserve treatment, and so I think that these people pushing these unregulated medications are really taking advantage of people in their moments of vulnerability, where they want treatment. That's what I have issue with. It makes me angry."

Until additional research is completed, Varney said she remains concerned about the growing popularity of unregulated peptides.

"I will not prescribe them, but I'm going to be watching them carefully for adverse side effects. I'm going to be monitoring their labs and, most importantly, I'm going to make sure that I am talking about those lifestyle interventions that have known benefits from years of study — eating better and exercising more," she said.

The FDA's Pharmacy Compounding Advisory Committee is scheduled to meet next month to discuss the following seven unregulated peptides:

- July 23, 2026: BPC-157, KPV, TB-500, and MOTS-c.

- July 24, 2026: Emideltide (DSIP), Semax, and Epitalon.

Health experts say the outcome of those discussions could help shape future guidance on the use and regulation of peptide products that have become increasingly popular among consumers seeking weight loss, recovery and performance-related benefits.