You may have seen peptides promoted on social media, podcasts or wellness websites as the next breakthrough for everything from weight loss and muscle recovery to anti-aging and better brain health. While some peptide medications have become well-established treatments, many others are still being studied and aren't backed by strong evidence in people.
So how do you know what's proven, what's promising and what's simply too early to tell? Christine Bonarrigo, PharmD, BCPP, weight management clinical pharmacist at Tufts Medicine Primary Care, explains what patients should know before considering peptide therapy.
What are peptides?
Peptides are short chains of amino acids, the building blocks of proteins. They naturally occur throughout the body and help regulate many important functions, including metabolism, hormone signaling, inflammation and tissue repair.
Some peptides have become FDA-approved medications that are supported by years of clinical research. For example, medications like semaglutide and tirzepatide are peptide-based drugs that have been extensively studied for treating obesity and type 2 diabetes.
Other peptides being marketed today are investigational. That means researchers are still studying whether they're safe and effective, and many have little or no high-quality evidence from human clinical trials.
Why are some peptides in the news?
The U.S. Food and Drug Administration (FDA) is currently reviewing several peptides to determine whether they should be added to the 503A Bulks List. This list identifies bulk drug substances that traditional compounding pharmacies may use when preparing compounded medications.
It's important to understand that being included on this list is not the same as receiving FDA approval.
FDA-approved medications undergo extensive review for safety, effectiveness and manufacturing quality. Compounded medications serve an important role for some patients, but they’re not reviewed by the FDA in the same way before they are dispensed.
What does the research say about these peptides?
Interest in several investigational peptides has grown rapidly, but the evidence varies widely.
BPC-157
BPC-157 is often promoted for tendon injuries, muscle recovery and digestive health.
Most of the research has been conducted in animals, with very little evidence from human studies. While the early findings are interesting, researchers don't yet know whether these benefits translate to people or what the long-term safety profile looks like.
KPV
KPV has been studied for its potential anti-inflammatory effects, particularly in inflammatory bowel disease and certain skin conditions.
So far, human research remains very limited, making it difficult to know how well it works or who may benefit.
TB-500
TB-500 is commonly marketed for tissue repair, injury recovery and athletic performance.
Current evidence comes primarily from animal studies, and there isn't enough high-quality research in humans to establish its safety or effectiveness.
MOTS-c
Researchers are studying MOTS-c for possible effects on metabolism, insulin sensitivity and healthy aging.
While early research is promising, much more human research is needed before it can be recommended for routine use.
Emideltide
Emideltide is an investigational peptide being studied as a possible treatment for obesity and metabolic disease.
Clinical trials are ongoing, and researchers are still working to determine how effective and safe it may be.
Semax
Semax has been studied primarily in Eastern Europe for cognitive function and stroke recovery.
Although some studies suggest potential benefits, larger, well-designed clinical trials are needed before firm conclusions can be made.
Epitalon
Epitalon is frequently marketed as an anti-aging therapy.
Despite these claims, there is currently no convincing evidence that it slows aging or extends lifespan in humans.
What are the potential benefits of compounded peptides?
For some patients, compounded medications may provide access to treatments when no FDA-approved option meets their medical needs. Compounding can also allow medications to be customized, such as adjusting a dosage or preparing a formulation that isn't commercially available.
However, whether a compounded peptide is appropriate depends on the individual patient and the available scientific evidence.
What are the potential risks?
One of the biggest concerns is that many investigational peptides simply haven't been studied enough in people.
Potential risks include:
- Limited evidence showing they actually work
- Unknown long-term safety
- Differences in product quality or potency between compounded products
- Uncertainty about side effects and drug interactions
Because these products have not gone through the FDA approval process, patients should understand that much more uncertainty exists than with approved medications.
What should patients ask before starting a peptide?
If you're considering a compounded peptide, Bonarrigo recommends asking your doctor three important questions:
- Is there good human evidence that this works for my condition?
- What are the known risks, and what do we still not know?
- Is there an FDA-approved treatment with stronger evidence?
These conversations can help you make informed decisions based on science rather than marketing claims.
The bottom line
Interest in peptides has grown much faster than the evidence supporting many of them. While researchers continue to study their potential, most investigational peptides still require larger, high-quality clinical trials before they can be considered proven treatments.
It's also important to distinguish investigational peptides from FDA-approved peptide medications, such as semaglutide and tirzepatide, which have been extensively studied and shown to be safe and effective for specific medical conditions.
If you're considering peptide therapy, talk with your doctor before starting treatment. Together, you can review the available evidence, discuss the potential risks and benefits and determine whether an FDA-approved treatment may be the better option for your health needs.
Your PCP is your partner in staying healthy. Whether you're considering a new treatment, managing a chronic condition or simply have questions about your health, they can help you make informed decisions.
