What Are Peptides and Why Is Everyone Talking About Them?
In keeping with the latest viral TikTok trends, I couldn’t help but notice the surge of content tagged with #peptides. This isn’t simply encouragement to eat more protein-rich foods like meat, fish, or eggs. Instead, the conversation has shifted toward pills, powders, tinctures, and even injections of various peptides, many of which were never covered in my dietetics training.
Naturally, that raised questions. If we’re not talking about the peptides that come from whole foods, what exactly are people taking? I dug into the literature to better understand what peptides are, how they’re being used, and what we actually know about their safety and effectiveness. Consider this a science-based reality check.
What Exactly Are Peptides?
Without getting too far into organic chemistry, peptides are short chains of amino acids, the building blocks of protein. While proteins can contain hundreds of amino acids, peptides are much smaller, typically made up of about 2 to 50 amino acids.
The distinction between proteins and peptides can be somewhat arbitrary, but for this discussion, it helps to think of peptides as very small protein molecules.
Where Do Peptides Come From?
Peptides are naturally formed when protein-containing foods such as meat, fish, eggs, dairy, legumes, and whole grains are broken down in the gut. Proteins (longer chains of amino acids) are digested into peptides (smaller chains of amino acids).
The human body also produces many peptides endogenously. These include hormones, neurotransmitters, and signaling molecules such as insulin, glucagon, and growth hormone-releasing peptides. They all play essential roles.
Because of their small size, peptides can bind to specific receptors and help regulate normal processes, including:
- hormone signaling
- metabolism and appetite regulation
- tissue repair and muscle growth
- immune function
How Are Peptides Used in Medicine?
Peptide therapeutics have been used in medicine for nearly a century. One of the earliest examples is insulin, discovered in the 1920s, which laid the foundation for the development of peptide-based medications. Many are well studied, tightly regulated, and prescribed for clearly defined clinical indications.
Peptide drugs are commonly used to replace or mimic naturally occurring hormones. Clear examples include insulin for diabetes management, glucagon for the treatment of hypoglycemia, and parathyroid hormone analogs used in osteoporosis care.
In metabolic health, peptide-based therapies such as GLP-1 receptor agonists are used to improve glycemic control, regulate appetite, and support cardiometabolic health.
Certain peptides are also used in oncology, where they may help target tumors, deliver treatments, or enhance diagnostic imaging by binding to specific receptors on cancer cells.
How Are Peptides Used in Health & Wellness?
Peptides used in health and wellness are far less defined and come with much less oversight and testing. They’re often marketed to improve appearance, boost performance, or support general well-being rather than to treat a specific medical condition.
Wellness-marketed peptides may be sold as injections, oral capsules or powders, nasal sprays, or topical creams. Some are compounded by pharmacies, while others are sold through online vendors, med spas, or performance clinics. Unlike FDA-approved peptide medications, dosing, purity, and consistency can vary widely.
Show Me the Data: Which Peptides Are Safe and Effective?
Because many peptides used in health and wellness are not FDA-approved and lack robust human clinical trial data, their safety and effectiveness can be difficult to assess. That said, some peptides have decades of clinical research supporting their role in improving health and wellness when used appropriately.
Oral Collagen Peptides
There is growing evidence supporting the use of oral collagen peptides for skin, hair, and joint health. Collagen peptides are small protein fragments derived from animal collagen, a key structural component of skin, cartilage, and bone.
A 2020 randomized, triple-blind, placebo-controlled trial found that freshwater marine collagen supplementation improved skin elasticity, hydration, and overall appearance in women. Similarly, a 2015 randomized controlled trial by showed increases in skin hydration and dermal collagen density, along with reduced collagen network fragmentation and visible improvements in skin aging.
More recently, a 2023 systematic review and meta-analysis examining 26 randomized controlled trials involving 1,721 participants reported that hydrolyzed collagen supplementation was associated with positive skin health outcomes, with effective doses typically ranging from 2–10 g per day.
Aside from potential allergic reactions, the risks associated with consuming oral collagen are generally low.
Topical Copper Peptides (GHK-Cu)
Copper peptides (GHK-Cu) are naturally occurring compounds made of a small peptide bound to copper. They are found in human plasma, saliva, and urine and play a role in tissue repair and skin health.
Research suggests copper peptides can stimulate collagen and elastin production, helping improve skin firmness, reduce the appearance of wrinkles, and enhance overall skin clarity.
Copper peptides are most commonly used topically in serums, creams, and sprays for the face or scalp, where they are generally well tolerated.
Dietary Peptides
This may go without saying, but peptides are naturally present in many everyday foods and are safe to consume as part of a regular diet. Common sources include meat and fish, beans, lentils, and soy, as well as oats, flaxseed, and hemp seeds.
Which Peptides Should Raise Concern?
Most emerging or experimental peptides marketed in skincare, fitness, or biohacking spaces should raise concern. Hundreds are sold online with outlandish health claims but little high-quality research. While a small number of peptide therapies are FDA-reviewed and clinically appropriate, many are unregulated and carry potential risks.
- Human growth hormone (HGH): Use outside approved indications is linked to insulin resistance, edema, joint pain, and possible abnormal cell growth.
- Growth hormone secretagogues (GHS): Peptides such as CJC-1295, sermorelin, tesamorelin, and MK-677 stimulate growth hormone release and may promote cancers.
The “Wolverine Stack”: A popular biohacking term referring to the use of BPC-157 and TB-500, promoted for injury recovery, tissue repair, and accelerated healing. However, these peptides are often sold as “research use only,” a major red flag that raises concerns about safety, lack of oversight, and potential cancer risk.
Considerations for Your Practice
As peptides gain popularity, expect more patient questions, and confusion. A key role for clinicians is helping patients distinguish between food-derived peptides, FDA-approved peptide medications, and wellness-marketed peptides, which differ greatly in regulation and risk.
Focus conversations on indication and evidence. FDA-approved peptide therapies have clear benefits and safety data, while most wellness peptides lack robust human trials, standardized dosing, or long-term safety data.
It’s reasonable to acknowledge interest while setting clear boundaries around what is (and isn’t) supported by science.
Be especially cautious with growth hormone, growth hormone secretagogues, and experimental injectable peptides. When in doubt, redirect patients to basics of adequate protein from whole foods, resistance training, sleep, and evidence-based medical care.
Integrating Evidence-Based Nutrition Care
Looking to integrate evidence-based nutrition counseling into your practice? I work with healthcare teams to translate research into practical, patient-centered care. Let’s connect.
- Forbes J, Krishnamurthy K. Biochemistry, Peptide. In: StatPearls. Treasure Island (FL): StatPearls Publishing; August 28, 2023.
- Jakubczyk A, Karaś M, Rybczyńska-Tkaczyk K, Zielińska E, Zieliński D. Current trends of bioactive peptides—new sources and therapeutic effect. Foods. 2020;9(7):846. doi:10.3390/foods9070846
- Wang, L., Wang, N., Zhang, W. et al. Therapeutic peptides: current applications and future directions. Sig Transduct Target Ther7, 48 (2022). https://doi.org/10.1038/s41392-022-00904-4
- Pu SY, Huang YL, Pu CM, et al. Effects of oral collagen for skin anti-aging: a systematic review and meta-analysis. Nutrients. 2023;15(9):2080. doi:10.3390/nu15092080
- Asserin J, Lati E, Shioya T, Prawitt J. The effect of oral collagen peptide supplementation on skin moisture and the dermal collagen network: evidence from an ex vivo model and randomized, placebo‐controlled clinical trials. J of Cosmetic Dermatology. 2015;14(4):291-301. doi:10.1111/jocd.12174
- Evans M, Lewis ED, Zakaria N, Pelipyagina T, Guthrie N. A randomized, triple-blind, placebo-controlled, parallel study to evaluate the efficacy of a freshwater marine collagen on skin wrinkles and elasticity. J Cosmet Dermatol. 2021;20(3):825-834. doi:10.1111/jocd.13676
- Pickart L, Margolina A. Regenerative and Protective Actions of the GHK-Cu Peptide in the Light of the New Gene Data. Int J Mol Sci. 2018;19(7):1987. Published 2018 Jul 7. doi:10.3390/ijms1907198
- Chakrabarti S, Guha S, Majumder K. Food-Derived Bioactive Peptides in Human Health: Challenges and Opportunities. Nutrients. 2018;10(11):1738. Published 2018 Nov 12. doi:10.3390/nu10111738
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