Peptides Promise Health Benefits, But Do They Actually Work?

What are peptides?

Dr. Goldwaser: A peptide is a small chain of amino acids, and amino acids are the building blocks of protein. Our body makes peptides naturally, but you can also get them outside the body, for example from food, vitamins or medications. 

Dr. Tchang: Like protein, peptides can do anything and everything in the body. There are thousands of types. They can act as hormones, boost the immune system, and help control weight management. Even allergens like cat dander or dust contain peptides that trigger allergic reactions. So, peptide is an umbrella term — I think people are just trying to figure out how we can consume or inject peptides for the betterment of our health.

What is the difference between a peptide and a protein?

Dr. Tchang: If you break proteins down into smaller pieces, those pieces are peptides. Think of peptides like Lego blocks; when you put them together, you create a protein.

What are the health benefits of peptides?

Dr. Tchang: The peptides I prescribe are FDA approved to treat diseases like diabetes or obesity. Insulin and GLP-1s are peptides, and in those cases, we have clear, scientific data showing they work. The GLP-1s, like Wegovy, Ozempic, Mounjaro or Zepbound, help people lose weight, improve satiety, and reduce food noise. And in some cases, they can treat sleep apnea and protect people against liver disease and cardiovascular disease. 

Dr. Goldwaser: I think there is promise for peptides to be used for muscle recovery by reducing inflammation and to support muscle growth by signaling the body to produce growth hormones. But for now, it’s cautious optimism. The anecdotal reports and animal studies make these peptides seem like a miracle cure, but there are no large-scale human clinical trials or reputable data to support that claim.

How are peptides taken? 

Dr. Tchang: The majority of FDA-approved peptides, like insulin and GLP-1s, are taken in the form of injections. When peptides are taken by mouth, they are broken down into amino acids and the body absorbs it as such. We are just starting to figure out how to make GLP-1 pills that won’t break down in the body.  

What are the risks associated with peptides?

Dr. Goldwaser: The biggest risk is the unknown. There is a theoretical risk that peptides could accelerate the growth of an undiagnosed cancer cell. Other risks may include hormone imbalances or water retention. Most importantly though, a lot of these products could be contaminated because they're from unregulated areas or the “gray market”. This stuff could make you feel great by design, but really it's harming your body. 

I try to caution everybody that social media influencers often don't have medical degrees or training. If you're going to use peptides, do it under the guidance of a physician who can monitor your blood work and your vital signs and ensure your restorative treatment isn't actually doing long-term damage.

What peptides are FDA approved?

Dr. Tchang: Peptides are regulated the way other medications are regulated. The FDA approves them based on a series of clinical trials that prove efficacy and most importantly safety. 

Besides GLP-1s and insulin, another peptide approved by the FDA is tesamorelin, which is a synthetic growth hormone. It is approved to reduce excess abdominal fat in adults with HIV who have lipodystrophy, a condition in which excess fat develops in different areas of the body, particularly the liver and stomach. But some people are using tesamorelin just for general health purposes. They think the growth hormone will be helpful for performance enhancement, reducing fat and increasing metabolism, but we do not have data on the safety and efficacy of tesamorelin in the general healthy population.

What are “research peptides” and how are they different?

Dr. Tchang: Research-grade peptides are largely unregulated for human use in terms of sterility, purity and safety compared to FDA-approved peptides. Research-grade peptides are based on lab studies or preclinical studies in animals, like mice or monkeys — so the quality control is not the same. With FDA-approved peptides, what you buy, what’s in the bottle, is actually what’s on the label and nothing else.

What does it mean to “stack” peptides?

Dr. Goldwaser: Stacking is the practice of putting two or more peptides together to enhance the outcomes. One example is known as the “wolverine stack” which combines peptides related to growth hormones and for recovery. People are using them simultaneously instead of in a series. 

Dr. Tchang: When people stack peptides, we don't know the consequences. There's a reason why we doctors ask patients, what medications are you taking and what supplements are you taking? It’s because we want to look for any drug interactions. If there's a drug interaction, or a supplement interaction, it might cause side effects for you, and we want to avoid that.

How do peptides work in the body for muscle growth and recovery?

Dr. Goldwaser: A lot of athletes of all calibers, ages and types are asking me about how peptides are going to enhance performance. My patients are looking for a fast track to recovery, and most are trying to heal stubborn injuries like tendonitis, ligament tears or arthritis. They also just want to improve their body composition and slow down the effects of aging.

For muscle growth, lab data and animal studies show that certain peptides stimulate the pituitary gland to release natural pulses of growth hormone. For recovery, they can trigger angiogenesis, which creates new blood vessels to bring nutrients to damaged tissue — think of these peptides like supervisors or managers in the body that send a construction site team to that area to heal it. 

But again, the big problem is a lack of evidence that these peptides work on humans. We are in the early stages, and we need better protocols.

What is a good substitute for peptides that can help build muscle? 

Dr. Goldwaser: I recommend creatine. Creatine is very safe, well studied, and it helps with muscle building and muscle bulk.

I also tell everybody there's nothing that substitutes for good nutrition, good hydration, good sleep and recovery, and regular exercise. When you treat your body like a well-oiled machine, you'll get results.