Peptides for Human Health

Corey Schuler, PhD, FNP, CNS

Peptides are having a moment. From Semaglutide’s headline-making effects on appetite and weight, to BPC-157’s buzz for gut and joint repair, these short chains of amino acids are redefining an era. But peptides are far from new. Clinicians have been harnessing their power for decades, often under different names and with different intentions. 

The message, however, is the same: How can we best work with the body’s own messaging system rather than against it. Traditional and integrative practitioners have used glandular extracts from animal sources (such as the thyroid, thymus, pancreas, or adrenal glands) based on the general principle that “like supports like.”* The belief was that consuming extract from a particular organ would support the function of the same organ in the human body.* Modern research suggests there may be some physiological truth to these hypotheses. For example, glandular extracts do contain short chains of amino acids called peptides, which can act as signaling molecules with downstream effects.* Peptides have a high affinity for their molecular targets, which means relatively low doses can provide biological benefits, and they are easily metabolized into non-toxic products.* [1]

Because they are smaller than whole proteins, peptides are also typically easier to absorb than proteins, although most peptides are isolated from a whole protein source. Some bioactive peptides support blood glucose, blood lipid, or blood pressure balance, while others support immune function or healthy aging processes.* [2]

Here, we will review established clinical uses for peptides, and then explore a few experimental peptides where human trial data is drawing more scientific interest.

Peptide Hormones

Some of the most well-known peptide therapeutics have been around for some time, and are supported by very high-quality human clinical trials. Insulin is a classic example of an essential peptide hormone for glucose signaling throughout the body.

Another increasingly popular group of peptide hormones are GLP-1 (glucagon-like peptide-1) analogues. These synthetic peptides mimic an endogenous peptide hormone which stimulates insulin secretion, suppresses appetite, and slows gastric emptying.* [3] These peptides have been designed to last significantly longer than natural GLP-1 in circulation, as they are resistant to breakdown by the enzyme DPP-4. This enzyme breaks down endogenous GLP-1 quickly.* [3] While these analogs were originally designed and marketed to patients with poor insulin sensitivity, they have since taken over the weight management market.* 

While some nutrients, food, and dietary plans can modestly support endogenous GLP-1 secretion within your body, it is important to note there are no nutritional or dietary sources of GLP-1 analogs or mimics. [4]

Skin & Healthy Aging

One of the most common uses of peptides is for skin health, particularly via oral collagen peptides (hydrolyzed collagen or collagen-derived peptides) in support of youthful looking skin.*

A 2019 review of eleven studies with a total of 805 patients found both long- and short-term use of collagen peptides supported wound healing and healthy skin aging, Specifically, these oral collagen supplements promoted skin elasticity, hydration, and dermal collagen density.* [5]

There are numerous proposed mechanisms behind these effects. First, hyaluronic acid is the primary molecule supporting skin moisture, and its endogenous production tends to decrease as we age.* However, specific collagen peptides have been found to be effective to increase water-binding glycosaminoglycans and collagen content of human skin. This supports overall moisture, hyaluronic acid, and hydroxyproline, enhancing water retention and skin structure.* [6]

Skin elasticity on the other hand, is associated with collagen content in the dermal extracellular matrix. Again, a common characteristic of aging is a decrease of collagen production by fibroblasts within the skin, and the subsequent collapse of the matrix causes a loss of elasticity and thinner, drier, more wrinkled skin.* [7] Animal studies have demonstrated that collagen hydrolysate administration can protect epidermal barrier function and skin elasticity.* [6]

Musculoskeletal Health

Peptides (including collagen) may also support joint and muscle health, bone integrity, and possibly injury recovery.* As with skin, collagen loss is a common characteristic of aging in the joints. Similarly, the hypothesis is that protecting or replenishing lost collagen may support mobility and comfort in joints, much like it would support a youthful appearance in skin.*

In a small study of older men at risk of muscle wasting, the addition of collagen hydrolysate showed a positive trend of increasing muscle mass and strength.* Collagen peptides have been linked to joint comfort in both animal and human studies.* [8]

Bioactive peptides isolated from fava beans (Vicia faba) have also shown some promise in the field of exercise performance.* One randomized, double-blind, placebo-controlled study of young men demonstrated that fava bean peptides supported higher myofibrillar protein synthesis rates when recovering from an injury.* [9]

Immune Modulation and Peptides

Beyond structural support, peptides are increasingly recognized for their roles in modulating immune responses.* There are small peptides produced naturally or synthetically that can both support healthy gut microbes and modulate immune signals.* A number of human trials have shown that certain food-derived peptides can influence cytokine production, immune cell function, and gut barrier integrity.* [10]

Experimental Peptides

One peptide with promise is BPC-157 (Body Protection Compound-157). BPC-157 is a 15-amino acid peptide derived from human gastric juice. As the subject of multiple preclinical trials, BPC-157 has demonstrated potential for pleiotropic benefits, including tissue repair, cytokine modulation, gut barrier protection, and even mood and neuropsychiatric benefits.* [1] As most of these studies are small and preliminary, long term-safety and optimal dosing remain to be determined.

Tesamorelin is a synthetic peptide designed to mimic growth hormone-releasing hormone (GHRH).* Tesamorelin stimulates the release of endogenous growth hormone (GH) by the anterior pituitary gland. In adults, this may stimulate a reduction in visceral adipose tissue and an increase in the density of skeletal muscle.* [11] Johns Hopkins University is currently conducting another study to investigate the use of Tesamorelin to support nerve regeneration and functional nerve recovery in humans, as GH has been shown to provide these benefits in animal studies.* 

There are other GH or GHRH analogue/secretagogues that have been studied in human trials. Ipamorelin, CJC-1295, and GHRP-6 are all slightly different peptides designed to signal GH through different pathways.* For example, CJC-1295 has a much longer half-life than Ipamorelin, because it conjugates to serum albumin. [12] CJC-1295 however, is a GHRH analog, and GHRP-6 is a ghrelin mimetic, so it stimulates GH secretion through the GH secretagogue receptor (GHS-R).* [13] Because of these differences, employing multiple peptides at once could potentially provide a synergetic effect on the GH axis with hypothesized benefits to muscle strength, adipose tissue, metabolism, or nerve health.* [14]

Final Thoughts

Peptides play a critical role in both structure and function of the human body, and manipulation of these peptides is a promising avenue for supporting human health.* It is also clear that the umbrella of “peptides for human health” encompasses a wide range of structures with an even wider range of activities.*

Peptides are not the answer to every health concern, but depending on the specific peptide, they may deliver measurable benefits for skin, joints, muscles, cytokine response, metabolic health, immune function, and so much more.*

Disclaimer:

The information provided is for educational purposes only. Consult your physician or healthcare practitioner if you have specific questions before instituting any changes in your daily lifestyle including changes in diet, exercise, and supplement use.

Corey Schuler, PhD, FNP, CNS has dedicated his career to advancing the science and clinical art of integrative medicine and serves as director of medical affairs for Allergy Research Group. He is a family nurse practitioner and practices holistic primary care at Synergy Family Physicians in White Bear Lake, Minnesota.