Peptides are short chains of amino acids, the building blocks of proteins. A search for “CA peptides” may be a mistyping of “Cu peptides,” as Cu is the chemical symbol for copper. This article focuses on copper peptides, particularly the most studied form known as GHK-Cu, exploring its composition, function, and applications.
The Composition of Copper Peptides
The most well-researched copper peptide is GHK-Cu, a complex formed when a copper(II) ion binds to a tripeptide called Glycyl-L-Histidyl-L-Lysine (GHK). This naturally occurring compound was first identified in human plasma. The GHK tripeptide acts as a carrier, delivering copper ions to cells and making the trace element more bioavailable for use in enzymatic processes. For commercial use, it is synthesized in a lab to ensure purity and stability.
The concentration of GHK-Cu in the body changes over a person’s lifetime. In youth, plasma levels are estimated to be around 200 nanograms per milliliter at age 20. These levels steadily decrease with age, dropping to approximately 80 ng/mL by age 60. This decline is thought to contribute to signs of aging, prompting scientific interest in its restorative potential.
Biological Mechanisms
One of its most documented roles is in tissue remodeling and wound healing. It stimulates the synthesis of components in the extracellular matrix, the scaffold that provides structural support to cells. This includes increasing the production of collagen and elastin, which give skin its firmness and elasticity, and glycosaminoglycans, which help maintain skin hydration.
Beyond building new tissue, GHK-Cu helps remove damaged tissue. It modulates the activity of matrix metalloproteinases (MMPs), enzymes that break down old proteins in the extracellular matrix. This process clears away scarred tissue and makes way for healthier tissue generation. This dual action of synthesizing new components and clearing out old ones allows for more effective tissue regeneration.
The peptide also exhibits anti-inflammatory effects by reducing the presence of pro-inflammatory cytokines. These are signaling molecules that can cause inflammation. By calming these responses, GHK-Cu helps protect tissues from damage during injury or from chronic inflammation, which is beneficial for wound healing and certain skin conditions.
GHK-Cu also functions as an antioxidant and promotes angiogenesis, the formation of new blood vessels. It supports the activity of the enzyme superoxide dismutase (SOD), a powerful antioxidant that protects cells from oxidative damage. The growth of new blood vessels is necessary for supplying oxygen and nutrients to damaged tissues, facilitating repair.
Applications in Cosmetics and Health
In the skincare industry, GHK-Cu is widely used in anti-aging formulations. These products are designed to improve skin firmness, enhance elasticity, and reduce the appearance of fine lines and wrinkles, counteracting the age-related decline in the skin’s structural proteins.
In hair care, copper peptides are incorporated into serums and treatments to support scalp health and encourage hair growth. By improving the environment for hair follicles and potentially prolonging the growth phase of the hair cycle, these products may help improve hair density and thickness.
Copper peptides are also utilized for their wound care benefits. Formulations containing GHK-Cu can be applied to skin wounds to support the natural healing process, accelerate wound closure, and potentially reduce scar tissue. This makes it a useful ingredient for post-procedure recovery or general first aid.
Scientific Evidence and Safety Profile
Evidence supporting copper peptides comes from laboratory (in-vitro) studies and small-scale human clinical trials. In-vitro research has established its effects on stimulating collagen in fibroblast cells, while human studies have demonstrated visible improvements in skin appearance. For instance, one 12-week study noted that a GHK-Cu cream improved collagen production in 70% of the women treated. While promising, evidence for applications like hair growth is still emerging, with some studies showing results comparable to established treatments.
GHK-Cu is considered safe for topical use in the concentrations found in cosmetic products, which often range from 0.05% to 1%. The most common side effects are mild and may include temporary skin irritation, redness, or itching, particularly for individuals with sensitive skin.
Higher concentrations could lead to increased irritation, so new users should perform a patch test before applying a product to a large area of skin. Following the manufacturer’s usage instructions helps ensure proper application and minimizes risk. Injectable forms of GHK-Cu require medical supervision due to greater risks.