What Are Peptides?

Dr. Phill Richardson
Apr 16
9 min read

Updated: May 3

What Are Peptides?

Peptides and proteins are both composed of amino acids linked in long chains through peptide bonds. What primarily distinguishes peptides from proteins is their size. Although there’s no strict threshold, peptides typically consist of fewer amino acids and are significantly smaller. When a peptide chain exceeds roughly fifty amino acids, it usually begins to fold into complex shapes known as secondary structures. These folded structures mark the transition into what we classify as a protein. Peptides, by contrast, are usually linear and show minimal folding, though simple loop formations may occur.

Peptides can be seen as simplified versions of proteins, but their biological significance goes far beyond that comparison. Research has shown that peptides serve as signaling messengers that help regulate major biological systems. They influence critical processes such as immune response, growth hormone release, tissue regeneration, and the development and movement of nerve cells. In essence, peptides serve as switches that activate or deactivate vital biochemical pathways and are essential for proper physiological functioning.

It’s also worth noting that peptides are a regular part of our daily nutrition. Foods like eggs, dairy, legumes, meat, oats, and grains naturally contain peptides and proteins. In addition, many modern supplements, functional foods, and energy drinks are fortified with peptides designed to support muscle growth, improve digestion, and enhance overall vitality. Well-known peptides commonly found in these products include collagen and creatine.

Peptide Classes

Peptides are often grouped by their biological function. Some common classifications include antimicrobial peptides, peptides used in vaccines, and those studied for cancer treatment. However, many peptides do not fit neatly into a single category. For example, peptides that support brain function may also influence immune regulation. Similarly, peptides that promote skin health often overlap with those involved in tendon repair. Categorizing peptides based solely on the tissue where they are found is generally not effective because many peptides act systemically and are present in various tissues.

A more functional way to group peptides is by their primary biological effect. This can include healing peptides, peptides that support growth, peptides linked to longevity, those that promote fat metabolism, or those with anti-inflammatory effects. Even so, most peptides exhibit multiple effects across these categories. Take BPC-157 as an example—it’s both a regenerative and anti-inflammatory peptide.

Rather than focusing on labels like “brain peptide” or “healing peptide,” a more insightful approach is to examine which biochemical pathways a peptide influences. For instance, sermorelin acetate affects the growth hormone axis, which can result in increased muscle mass, reduced body fat, cellular regeneration, and more. Understanding the mechanisms behind a peptide’s activity provides a clearer picture of its benefits and potential side effects than simply knowing the tissue it interacts with.

What Are Peptides Being Used For?

Peptides are now found in a wide range of applications, from anti-aging creams and cosmetics to advanced medical therapies. Knowing how peptides work is not only valuable for healthcare professionals and researchers but also for individuals who are proactive about their health and aging. While the number of health-promoting peptides is steadily increasing, it can be overwhelming to sort through the many options. If you’re looking to better understand which peptides support wellness, it helps to focus on those that have been shown to reduce inflammation, support tissue healing, fight infections, and slow down biological aging.

What to Know About Peptides?

One of the most important insights about health peptides is that they play a key role in nearly every major function in the body. Scientific studies over the past few decades have revealed that peptides are involved in everything from aging and immune regulation to cognitive enhancement and metabolic balance. Far from being mere research tools, peptides have demonstrated their ability to restore equilibrium within biological systems.

A great example is sermorelin, a peptide that stimulates the body’s natural release of growth hormone (GH). Scientific findings suggest that the age-related decline in GH isn’t just a symptom of aging—it may also contribute to it. Using peptides like sermorelin to restore more youthful GH levels has been associated with increased muscle mass, reduced fat accumulation, improved heart function, enhanced memory and sleep, and more.

Peptides like collagen have long been included in cosmetic formulations, especially in skin creams. Meanwhile, compounds such as PT-141 and BPC-157, though studied for years, are only now gaining broader attention. As scientific interest continues to grow and funding increases, peptides are expected to play an even more central role in future healthcare and wellness strategies.

What Are the Benefits of Health Peptides?

Research in both animal and human models shows that health peptides can have a host of beneficial effects. Examples of those effects include:

• Reduced inflammation 2,3,

• Enhanced wound healing 4,

• Reduced scar formation 5,

• Increased muscle mass and strength 6,7,

• Increased rate of fat burning 8,

• Improved insulin resistance 9,

• Increased bone strength and density 10,

• Improved immune function 11,

• Improved sleep 12,

• Improved memory and concentration 13,14, and

• Better skin tone and elasticity 15–17.

Slowing the Aging Process

Certain peptides, such as sermorelin and epithalon, have demonstrated the ability to impact aging at the DNA level. These compounds activate the enzyme telomerase, which plays a key role in maintaining and repairing telomeres — the protective caps at the ends of DNA strands. As telomeres naturally shorten over time, cells lose their ability to divide and regenerate, leading to tissue decline. By preserving telomere integrity, peptides like sermorelin can help slow this degenerative process.

Beyond telomere protection, peptides also help delay aging by reducing oxidative stress — one of the leading causes of cellular damage. Peptides including sermorelin, epithalon, ipamorelin, CJC-1295, and BPC-157 exhibit antioxidant properties that help prevent the types of DNA damage associated with cancer, cardiovascular disease, neurodegeneration, and other age-related conditions.

Some peptides also improve the visible signs of aging. Collagen, melanotan, PT-141, and the peptides mentioned above have shown benefits such as reduced wrinkle depth, improved skin elasticity, enhanced body composition, and more radiant skin tone. These cosmetic improvements can occur independently of changes at the cellular aging level.

Faster Wound Healing

Peptides enhance wound healing through several mechanisms — including activating growth hormone pathways, increasing cell migration, reducing inflammation, and promoting the production of extracellular matrix components. Notable examples include VIP, KPV, BPC-157, sermorelin, and hexarelin. Studies show these peptides can strengthen healed tissue and minimize scarring.

Among these, BPC-157 is particularly recognized for its regenerative effects, especially in tendon repair. Tendons are notoriously slow to heal, yet BPC-157 accelerates the process and improves healing quality, leading to stronger outcomes compared to placebo-treated groups.

Some peptides such as TB-500 and KPV also have antimicrobial properties, which support infection-free wound recovery. Since infections can significantly hinder the healing process, peptides that minimize microbial interference can dramatically improve recovery speed and effectiveness.

Other peptides promote angiogenesis — the growth of new blood vessels — ensuring rapid delivery of nutrients and immune cells to the injury site. These mechanisms make peptides particularly valuable in the context of chronic conditions like diabetes, where healing is often impaired.

Building Lean Body Mass

Improving lean body mass involves building muscle, reducing fat, and increasing bone density. This shift supports overall health and lowers the risk of chronic illnesses such as metabolic syndrome, type 2 diabetes, and cardiovascular disease.

Several peptides support one or more of these processes. Sermorelin, CJC-1295, and GHRP-2 influence the growth hormone axis, which helps increase muscle mass, strengthen bones, and burn fat. Ipamorelin shares similar benefits and is being explored for its role in preventing osteoporosis.

Other peptides like AOD9604 and Tesofensine act as targeted fat burners. While they indirectly support muscle and bone maintenance by reallocating energy resources, their primary action is reducing body fat. When combined with proper nutrition and exercise, these peptides can improve insulin sensitivity, glucose tolerance, and overall metabolic health.

The growing body of research confirms that peptides can meaningfully improve body composition. Ongoing studies aim to better understand how they affect the underlying mechanisms of muscle growth, fat metabolism, and bone density — key factors in long-term vitality.

Summary of Peptides

Peptides are naturally present in many foods and are often added to nutritional supplements and performance-enhancing products. They influence a wide range of physiological functions — from tissue repair and immune regulation to cognitive performance and healthy aging.

Scientific interest in peptides continues to expand, with ongoing discoveries in their therapeutic potential and improved methods of storage, transport, and administration. In the years ahead, peptides are expected to play an increasingly central role in preventative health, regenerative medicine, and personalized wellness.