A drug that helps people live longer, recover faster, feel more energetic and maintain strong muscles, bones and joints would have obvious appeal.
Such is the promise of wellness peptides—at least according to some celebrities and social media influencers who have helped fuel a surge in their popularity.
Peptides are molecules that serve a variety of functions in the body. They also form the basis of several medications approved by the U.S. Food and Drug Administration (FDA).
But many unapproved peptide products promoted on social media are a different story. As interest in them has grown, so have questions about their effectiveness and safety. Many have not been evaluated in well-designed human clinical trials, leaving their potential benefits and harms poorly understood.
“Most of the medical community considers these investigational and doesn’t recommend them as a substitute for standard care,” says Richard Cartabuke, MD, with Cleveland Clinic’s Department of Executive Health.
What Are Peptides?
Peptides are short chains of amino acids, the building blocks of proteins. Peptides typically contain two to 50 amino acids; proteins generally contain longer chains that fold into complex structures.
Many peptides act as signaling molecules—chemical messengers that transmit information between cells. Depending on the peptide, they can help regulate processes such as metabolism, digestion, immune responses, and tissue repair.
Their effects depend on their amino acid sequence, structure, and biological target, and a benefit demonstrated for one peptide does not establish a benefit for another.
Types of Peptides
When discussing peptides with his patients, Dr. Cartabuke distinguishes among several overlapping categories:
- Food-derived bioactive peptides. Digestion or processing can release peptides from protein-rich foods, including dairy products, fish, legumes, seeds, whole grains, and soy. Some have biological activity, but evidence for their health benefits varies according to the peptide and its intended use.
- Collagen peptides. Collagen is the most abundant protein in your body and helps support skin, bones, cartilage, tendons, and other connective tissues. Supplements contain collagen broken down into smaller peptides and are marketed for skin and joint health, among other uses. However, eating collagen does not directly replace collagen in a particular tissue. “You can get them in many different forms, and there’s varying evidence for how they may impact your health,” Dr. Cartabuke says. “But generally, they have a safety profile that is favorable.”
- Peptide hormones. Several important hormones are peptides or proteins. Examples include insulin, which helps to regulate blood sugar; human growth hormone, a protein hormone that affects growth and metabolism; and vasopressin, which helps the kidneys retain water and also influences blood pressure. One particular peptide hormone that has generated interest in recent years is glucagon-like peptide-1 (GLP-1), which, among other functions, helps to regulate appetite and blood sugar. The popular weight-loss drugs known as GLP-1 agonists mimic the effects of this hormone.
- Peptide-based medications. Peptides and related proteins can be manufactured for medical use, and their benefits and risks have been evaluated for specific indications. FDA-approved examples include insulin, GLP-1 receptor agonists, and certain osteoporosis medications. Peptides used in cosmetic skincare products belong to a different regulatory category.
- Unapproved research compounds. Products sold online or marketed for wellness include BPC-157, TB-500, MOTS-c, thymosin alpha-1 and GHK-Cu. (Another product, MK-677 [ibutamoren], is often marketed alongside these products but is not a peptide.) Some products carry labels such as “for research purposes only,” but this labeling does not establish that they’re suitable for human use. Sellers promote them for injury recovery, fat loss, skin health, and other purposes for which clinical evidence is limited or lacking.
“I tell people that we need to be precise when having a conversation about peptides,” Dr. Cartabuke says. “When you’re talking about food-derived and collagen peptides and peptide medications, there is legitimate human evidence for them. For these popular injectable compounds, most of the data comes from animal studies that are small and methodologically weak, so these claims about benefits really remain unsubstantiated.”
How Do Peptides Work in the Body?
Because peptides have different biological targets and functions, their benefits and risks must be evaluated individually.
“You can’t really generalize to say peptides do this or that,” says Myles Spar, MD, with The WNDER Lab, a New York-based longevity research and health organization. “They’re as varied as there are varied cells in the body. Some peptides help with tissue regeneration and healing, some with increasing blood flow, some with improving metabolic health, insulin sensitivity and weight loss. Some help with brain function and immune function. Some help with tanning in the body or even sexual arousal.”
Common Uses and Claimed Benefits
Products containing collagen peptides or copper peptide (GHK-Cu), are marketed for smoothing wrinkles and improving your skin’s hydration, elasticity and appearance.
Many peptide products are promoted for weight loss, but only certain ones have substantial evidence supporting their use for this purpose—namely, the FDA-approved GLP-1 agonists.
Collagen peptide supplements and several experimental compounds are promoted for building muscle, improving athletic performance and aiding recovery after workouts, injury or orthopedic surgery. Some of these products are “gray-market” peptides, such as MOTS-c and the so-called “Wolverine” stack, which combines BPC-157 (a synthetic version of a gastric peptide promoted for tissue healing) and TB-500, a manmade peptide designed to mimic a natural human peptide (thymosin beta-4) that helps with tissue repair. Others—including synthetic CJC-1295, ipamorelin, and the nonpeptide compound MK-677—are promoted as treatments to stimulate growth hormone release.
Moreover, BPC-157 and another synthetic peptide, thymosin alpha-1 (a naturally occurring peptide produced in the thymus gland) are touted as immune system boosters.
The Hype vs. the Evidence
While the efficacy and safety of FDA-approved peptide medications have been demonstrated in rigorous clinical trials, Dr. Cartabuke and Dr. Spar emphasize marketing claims for many experimental products outpace the human evidence.
Some data suggest that collagen peptides do help to keep skin looking younger and may reduce pain and improve function in people with osteoarthritis. “Collagen makes up a lot of what supports the whole structure of our body, so it has a very high protein content,” Dr. Spar says. “However, there’s no evidence that eating collagen peptides creates bone or soft tissue any more than any other source of protein, like whey. It’s a decent source of protein, but it’s no better for skin, joints or bones. There’s no evidence to that effect.”
Similarly, the health claims surrounding the unapproved research compounds are based largely on evidence from preclinical studies looking at their effects in cell lines and animals, and the few studies in humans have involved small numbers of participants, Dr. Cartabuke cautions.
“I think the people who claim you’re going to derive benefit from these are getting their information from small, poorly conducted studies that don’t have a placebo or a randomized arm,” he says. “The information we have is from some promising animal studies. But we’re not mice, and that’s where a lot of the data comes from.”
Potential Risks and Side Effects
Since most evidence regarding unapproved peptide products comes from preclinical studies, the long-term safety in humans remains unclear. In fact, most have no long-term safety data, and some research suggests potential harm with certain products. For instance, in a recent review of compounds promoted for athletic performance and recovery, researchers pointed to clinical studies that identified a potential increased risk of heart failure and impaired glucose tolerance with MK-677.
“Overall, emerging peptide supplements lack clear evidence to support long-term safety or clinical efficacy for musculoskeletal health. Until more robust clinically relevant data are available, these supplements cannot be recommended as a replacement for or adjunct to established standards of care, and clinicians should counsel patients accordingly,” the study authors wrote (American Journal of Sports Medicine, online Aug. 11, 2026).
Moreover, one way that BPC-157 is believed to help with healing and athletic recovery is by increasing blood flow to damaged tissues through the formation of new blood vessels, or angiogenesis. Dr. Spar and Dr. Cartabuke point to theoretical concerns that this process could fuel tumor growth.
“One of the prime mechanisms underlying the way BPC-157 works is by increasing these pathways that support more blood flow,” Dr. Spar says. “Angiogenesis could be great if you have an injury, but it could be not-so great if you have a cancer looking for blood supply.”
Since these products do not undergo the same regulatory scrutiny as FDA-approved pharmaceuticals, there’s no guarantee as to their quality, potency and purity. And, questions remain about the dosing of these peptides, including the amounts and frequency, Dr. Cartabuke notes.
“What do you need in terms of a workup to be able to say this is the peptide that’s going to work best for you and at this dose and cadence? I don’t think we have any information that really tells us that, and that’s a problem,” he says.
“My patient experiences with peptides are across the board,” he continues. “There are individuals who didn’t really feel much of a difference, so they stopped within a couple of months. There are other individuals who swear by them and have continued them. Then, I’ve had two individuals who had bad reactions to them, so we immediately had them stop and the symptoms resolved. But it probably took almost six weeks for one and about 10 weeks for the other for those symptoms to fully go away.”
Advice for Patients
Dr. Spar says he frequently advises patients to “major in the majors,” or focus on beneficial evidence-based lifestyle habits that can improve your health. He emphasizes that any type of peptides or supplements should not be considered as a substitute for these behaviors.
“I tell patients that I don’t prescribe peptides, especially because there’s not a reputable source right now,” he says. “You have to major in the majors, really valuing your exercise, nutrition, sleep, brain health, social connections and your sense of meaning. Those all have hard proof as to their impact on health, a well-lived life and longevity.”
If you’re interested in peptides, Dr. Cartabuke recommends discussing the specific compound with your healthcare provider and, ideally, enrolling in a clinical trial investigating the efficacy and safety of experimental compounds.
“I’ve been encouraging people to find places that are doing these trials, because at least you’re getting a regulated dose of something that’s being studied and monitored appropriately by clinicians who are interested in seeing what the impact of the peptide will be,” he says. “If you’re doing it outside the bounds of a trial, it’s going to be on you to assess risk, and I don’t know how comfortable anyone would be in a scenario like that.”
How to Evaluate Peptide Products and Claims
If you’re considering using a peptide product or have been advised to use one, consider asking these questions:
- What specifically do you see in my laboratory profile, imaging or physical exam that would lead you to suggest this specific peptide for me?
- What is an effective dose and frequency of dosing?
- What evidence supports this dose and frequency of use?
- Is the dosing weight-based or dependent on muscle mass?
- Should I cycle on and off the peptide product?
- What are the potential side effects I should look for?
- Are there potential interactions with other medications?
- Would you be willing to consult with my physician about this? “If they’re not willing to collaborate and have a conversation, that should be a red flag,” Dr. Cartabuke says.
