Why are people taking peptides?

If you recognize the terms “microdosing,” “stack,” and “peps,” you may already have your eye on peptides, which are drugs composed of specific amino acids that supposedly have various health and “anti-aging” benefits for the body. And who wouldn’t these days? Wellness influencers are claiming to use them for all sorts of reasons, from fighting inflammation and reducing perimenopause symptoms to weight loss, body recomposition, and overall health. These non-experts are also calling themselves “certified peptide coaches” — a term that is as made up as it sounds — in order to share their info with others.

The question is, do peptides really work? And is it worth it for you to start taking them? We’re breaking it down, including what peptides are, their potential benefits, their very real risks, and where you should consider never buying them from.

Your body naturally contains amino acids, which are the building blocks of proteins. “Peptides are chains of amino acids that are signaling molecules,” says Dr. Christine Maren, D.O., a board-certified physician and functional medicine expert in Broomfield, Colorado. They travel around and affect multiple systems, including your heart, blood vessels, endocrine system, immune system, nerves, and brain. 

While many peptides exist in your body already, others are derived from food sources like animal products and plant proteins. Peptides can also be made in a lab for you to take, either as an injection or orally, for certain purposes. And this is not a new concept. 

“The classic example of a peptide is insulin,” says Chris D’Adamo, Ph.D., an expert in functional, integrative, and lifestyle medicine at the University of Maryland School of Medicine. Your pancreas manufactures insulin, but if you have diabetes, your body either doesn’t produce enough or can’t use it effectively. So, injectable insulin is considered a baseline diabetes treatment. 

GLP-1 receptor agonists, such as semaglutide (Ozempic, Wegovy) and the GLP-1/GIP medication tirzepatide (Mounjaro, Zepbound) are also peptide medications that mimic naturally occurring hormones in the body to help manage blood sugar and promote weight loss. And if you ever stirred collagen into a drink for skin or joint benefits, you’ve given yourself a peptide. 

But even though peptides have been used for decades, lately it seems like they’ve multiplied. The names now invading your social media algorithm and podcast stream sound as indecipherable as your parents’ wifi password: AOD-9604, BPC-157, CJC-1295, MK-677, Thymosin Alpha-1, and more. (So many more.) 

Unlike weight loss, these newer peptides are credited with more nebulous benefits, like "aging backward,” “longevity,” and “energy through the roof.” And it’s done with limited data and no large-scale studies to ensure safety or efficacy (meaning they may not help at all).

While it’s entirely possible that these peptides do what their proponents say they do, there just isn’t much proof. “There are surprisingly few human studies for many of these peptides,” says D’Adamo, who has done a pilot study on the oral peptide BPC-157. “While there may be a biological plausibility of their use, and animal studies, they’re not entirely convincing.” 

For instance, let’s look at BPC-157. Nicknamed the “wolverine peptide,” BPC stands for Body Protection Compound, and it’s a synthetic version of a peptide found in your stomach acid. It’s marketed as having antioxidant, anti-inflammatory, and healing properties, but the excitement outpaces the research. That doesn’t stop it from being popular with women with joint pain or who are going through menopause and think it can help them age well and feel good.

This is a perfect example of the disconnect between research and reality. Researchers might have some tepid excitement about peptides, but they want to see more science. However, if you were to read about an influencer’s stack (a combination of peptides someone takes regularly) on social media and all the benefits they’ve seen, you might think it’s case-closed, or that medicine has been hiding this longevity, weight-loss, and anti-aging secret all along. 

Keep in mind that this is just for non-FDA-approved peptides. FDA-approved medications like insulin and GLP-1s are backed by clinical trials that prove their benefits.

Even if peptides that aren’t approved by the FDA have some benefits, they aren’t proven to be safe. You’re using a substance that doesn’t necessarily contain what it claims to contain, has no proven safety or efficacy to begin with, and doing it without a prescription or medical supervision. “They also may have unknown risks because we haven’t researched them for a long time in large populations,” says Maren. And because they aren’t FDA-approved, people turn to unregulated websites to buy them — an approach that’s rife with risk. “[You don’t know] where you’re getting them from and if they’re being manufactured well,” says Maren. “It’s similar to the supplement industry as we don’t have a lot of regulation.”

And often peptide therapy is presented as a “menu” of sorts, where you create what’s known as a “stack” of peptides, or a combination of different ones, in order to build the body that you want from the inside out. This is why you might see reels online with titles like “5 peptides that changed my life.”

This practice of injecting multiple substances in your body can raise the risk of interactions, either with each other or with prescription or OTC medication you’re currently taking. “You’re adding extra risk,” says D’Adamo. “Does it mean extra harm? Not necessarily, but when you combine multiple peptides, you add more layers of uncertainty.”

Also, you may be ignoring something that needs legit treatment. For example, you may think you need a peptide because you’re tired, but it could be caused by a condition like hypothyroidism (a “slow” thyroid) which you need to treat with FDA-approved medication. “I’m not starting these patients on peptides, I’m fixing their thyroid,” says Maren.

Peptides are chains of amino acids that exist naturally in the body. While there are some FDA-approved peptide medications, like insulin and GLP-1s, there are also many unregulated options you can buy on the internet. Despite the impressive photos of influencers and celebs who claim that peptides are their secret sauce to looking and feeling great, these benefits may be overblown. “Some peptides show promise at the time, though I think right now it’s a bit overhyped,” says D’Adamo. “To expect anything that you’re taking exogenously [externally] will make you muscular or energetic all day is often based on a promise that’s too good to be true.”