Short Wave - Does the science of peptides live up to the hype?

Episode Date: July 22, 2026

Synthetic peptides are getting some serious hype, from fitness influencers on your FYP to people seeking new options for chronic conditions. And while the human body already makes peptides, like insulin and the hormone oxytocin, most of the viral synthetic peptides are not approved by the Food and Drug Administration. Scientists say that raises some big concerns about safety and efficacy. So ahead of this week’s FDA meeting to discuss seven commonly used peptides, we get into the science with health reporter Sarah Boden.Interested in more science behind health trends? Email us your question at [e-mail] public media with NPR+ and enjoy perks for over 25 podcasts like this one. It includes perks like bonus episodes, early access, archive access, curated playlists and sponsor-free listening. Learn more at plus.npr.org. See pcm.adswizz.com for information about our collection and use of personal data for sponsorship and to manage your podcast sponsorship preferences.NPR Privacy Policy

Hey, Shortwavevers, Regina Barber here. Maybe you've listened to us because we were in your daily drive and you were a casual acquaintance. Sadly, the daily drive is gone. So to keep this friendship going, we need you to be proactive and click to follow Shortwave in your podcast app. That way, you'll never miss the show, which is starting right now. You're listening to Shortwave from NPR. Today we're talking about peptides. They're all the rage among fitness influencers and people see.

seeking new options for other conditions like chronic pain. But lots of scientists have big concerns about their safety. So we're getting into it with health reporter Sarah Bowden, who's covered this topic for NPR. Hey, Sarah. Hey, thanks for having me. Yeah, I'm excited that you're here because I keep hearing about peptides. What is the deal? So a peptide is a string of amino acids that's smaller than a protein. And your body probably has millions of different peptides. And these peptides do different things like regulate immune function or grow certain cells, control hormones. For example, most people have heard of insulin. That's a peptide. The hormone oxytocin is also a peptide. And some of these peptides are getting even more time in the limelight this week because seven

commonly used peptides are up for consideration by the FDA's compounding pharmacy board. They're holding a two-day meeting later this week. Okay, so peptides, they're definitely not a new thing. No, no, definitely not. But what is new is that a lot of fitness influencers and tech bros and celebrities are really excited about synthetic peptides, which sources I spoke with would consider a type of medication. And anecdotally, people report various peptides have helped them with muscle recovery and immune function. Some people say different combinations of peptides can slow aging. Today on the show, the peptide promise.

Are peptides all they're cracked up to be? And is what you get from an influencer online the same as getting it from your doctor? You're listening to Shortwave, the science podcast from NPR. Okay, Sarah, let's get into it. What does data say about peptides? Is there proof to this idea that peptides can help people with muscle recovery and immune function, even slow down aging? I'm asking for a friend.

Totally. I mean, it depends on which peptide we're talking about because there are so many different peptides. For example, GLP1 weight loss drugs, the active ingredient in those is a peptide. And these medications have been studied for safety and efficacy. But with a lot of the more popular peptides, like maybe you've heard of BPC 157. Some people use it for muscle recovery from sports injuries. We just, okay, well, we don't know a lot about that peptide. And this. And this is a lot. And this. This is something I talked about with Paul Knopfler. He's a cell and molecular biologist at the University of California Davis. And he told me that most of the peptide research has been in animals or like cells and petri dishes. You know, we might predict, you know, substance XYZ is going to be really safe. It can be totally wrong. You know, like it might be fine in rats and mice, but it's toxic in people. So what does Paul mean by toxic in this case? Well, for example, something he's really worried about is angiogenesis. I don't know what that. that is. It's the physiological process that creates new blood vessels. And growing new blood vessels is great if you're trying to get over a sports injury like a torn ligament. But with angiogenesis, it's hard to monitor where else blood vessels are growing in your body. Probably most of us are walking around with cells that are partway down the road to becoming cancerous. And so

that's one of my worries with these peptides is that they'll kind of encourage moving along the pathway towards an actual cancer. So we just don't. have the data for this. Exactly. Good, bad. Otherwise, we don't know. So, Sarah, it feels like the obvious answer here is more research, like so much of our science stories. And like you said, peptides are already like available to us in our bodies. So since they're so popular, is they're going to be more research focused on peptides? Well, it's hard because you can't get a patent for these molecules unless they're ref formulated in some novel way. And pharmaceutical companies don't want to spend millions of dollars on drug trials unless they own the intellectual property.

Right. So if drug companies aren't doing a ton of R&D to make cells, then how are people getting these peptides? I mean, one of our producers told me that there was somebody selling them in her Pilates class the other week. Like, how was that happening? Literally a paper lunchbag full of syringes. Okay. So people should know that in the U.S. that for a lot of the more popular peptides, you cannot purchase medical grade quality. They are not approved by the Food and Drug Administration. So as a workaround, and maybe this is what the Pilates person was doing, people will go to the internet and get peptides from overseas vendors. But what they're getting are research grade. So these are peptides for studies like in mice or petri dishes. These are not peptides for people.

Quality control could be a really big issue. And I'm told that these substances might include solutions or contaminants that are toxic. This reminds me of recreational drugs a little bit, like people just DIYing longevity medicine and also just not knowing what's in him. Yeah, I mean, people aren't getting medical advice on how much of the peptide they should use or for how long they should take it the way you would talk to a doctor or a pharmacist who would advise you on how to use a certain medication. And now, you know, there are some physicians who prescribe peptides for things like inflammation. Their patients will get peptides from compounding pharmacies, but depending on the peptide, these compounding pharmacies may be providing unregulated drugs. And, I mean, with peptides, there are just so many layers of people doing things that are unsafe or maybe not legal,

which is why there are calls for the Food and Drug Administration to get involved and create some guardrails. Okay. Recently, FDA signed has recommended that these peptides should not be made available to the general public because of a lack of evidence. Basically, they have the same concerns that Paul does, that biologists I mentioned earlier. And the problem is when you have a moratorium on something that a lot of people want, they're going to do it anyways and likely go to the black or gray market where products are of lower quality. Oh, okay. So gray market peptides, by the way, are pepsies. peptides that are explicitly labeled for research or non-human consumption, but people are using them

as medication where black market peptides are counterfeit or illegal in some other way. This happened in the 1920s during prohibition. Right. Yeah. So some experts argue it just makes sense to be pragmatic and find ways to mitigate the danger. Like harm reduction? Yeah, exactly. You know, condoms, for example, can be considered harm reduction, wearing a helmet when you write a motorcycle, giving sterile needles to people who use illicit drugs. That's obviously harm reduction. So how would harm reduction work for peptides? So I talked to Scott Bruner about this. He's the CEO of the Alliance for Pharmacy Compounding. And Scott suggests that the FDA could make it so that peptides are only sold by

registered wholesalers or require some sort of enhanced disclosure to make sure people know these drugs are not well studied. We are talking about peptide drugs that you would only be able to get with a prescription from a licensed, legitimate provider, and that would be filled by legitimate state licensed pharmacies. So this way, it's not necessarily like all or nothing. Right. You know, Scott acknowledges there isn't rigorous safety data on peptides, but he argues that the regulations give people access to sterile peptides, which are better than what you'd get on the illicit market. Within that framework, FDA can collect data while ensuring that patients have a regulated pathway for getting these drugs rather than this rampant black market and gray market that

we have right now. So do you think that the compounding pharmacy advisory board will go for this argument, this kind of not all or nothing thing? Scott Bruner seemed optimistic. There are people on the advisory board who are from the compounding pharmacy industry. As NBR previously reported, some say that because these board members would benefit financially from changes to peptide regulations, there's a conflict of interest. But remember, the board is advisory. They don't make the final decision. Right. That's ultimately the FDA's call. So who is the FDA going to listen to the advisory board or the scientists if they disagree? I don't know. Historically, the FDA has given a lot of discretion to scientists.

But like other federal agencies, it's gone through major changes during the second Trump administration. Yeah, I know that a lot of career professionals have left the FDA. I also recently spoke with Howard Sclamberg about this. He's a partner at the law firm Arnold and Porter and a former FDA deputy commissioner. And when it comes to big decisions like what's happening with peptides, Howard says that stakeholders from across the agency will weigh in it. This includes lawyers who work really hard to keep the FDA from getting sued. So what does Howard think about the harm reduction argument?

He doesn't think it's compelling. If you accept that argument in its extreme version, you just basically have to wave your hand at anything that ends up being popular. Because like if that's the case, heroin or cocaine or really a lot of different drugs would be legal. FTA has always pulled between a public health impulse and a more libertarian impulse to let people decide what they want to do. But when something blows up, they get criticized in either direction. Also, he says that harm reduction argument could backfire. If peptides get the FDA's stamp of approval, it might cause more people to think peptides are safe when, again, we don't know if they're safe.

and this might encourage even more people to use them. And again, these are experimental drugs. We don't know a lot about them. So do you know when we might have a decision from the FDA? So Howard says that if the FDA decides to open the door to peptides, the proposed rule could come by the end of the year. Of course, there will be a public comment period, so that means the final rule would be sometime next year.

And even if this regulatory stuff goes really smoothly, Scott Bruner says supply chains will need some time to get up and running. Okay, so let's say all of that happens eventually. Will I be able to walk into my corner like drugstore and pick out a peptide stack the way I would buy ibuprofen or cough drops? No. No. I mean, if it works the way Scott envisions, you would need a prescription. And because peptides are experimental, it's unlikely that insurance will pay for your peptides.

so it probably won't be cheap. But it would be safer in that you at least know that you're getting the peptides you want and not some other stuff mixed in. So I want to like emphasize this is all like hypothetical. Nobody knows what's going to happen. But if the only people who can buy peptides from a compounding pharmacy are the people who can pay out of pocket for specialized medical care, it's conceivable that there will still be demand for gray market peptides.

Yeah. I think you might be. right. Sarah, thank you for this really thorough rundown of all things peptides and this impending FDA decision about them. I had a great time. Thanks for having me. If you like this episode, check out our episodes on fiber maxine and red light therapy. We'll link them in our show notes. This episode was produced by Rachel Carlson, edited by our showrunner Rebecca Ramirez and fact-checked by Tyler Jones. Jimmy Keeley was the audio engineer. I'm Regina Barbara, thank you for listening to Shortwave from NPR.