GHK-Cu

GHK-Cu (glycyl-L-histidyl-L-lysine:copper(II)) is a naturally occurring tripeptide-copper complex first identified in human plasma by Dr. Loren Pickart in 1973. It is found naturally in human blood plasma, saliva, and urine, with plasma levels declining significantly with age — from approximately 200 ng/mL at age 20 to 80 ng/mL by age 60.

This age-related decline in GHK-Cu levels has generated significant research interest, as the peptide has been shown to regulate the activity of over 4,000 human genes, with many of these genes involved in tissue repair, immune function, antioxidant defense, and stem cell biology. GHK-Cu is one of the most well-researched peptides in dermatology and has been incorporated into numerous commercial skincare products.

The copper ion in GHK-Cu is essential for its biological activity. Copper serves as a cofactor for numerous enzymes involved in collagen synthesis, elastin production, and antioxidant defense. The GHK tripeptide acts as a carrier that delivers copper to tissues where it is needed for repair and regeneration.

GHK-Cu exerts its effects through multiple mechanisms:

Collagen and ECM remodeling: GHK-Cu stimulates the production of collagen types I, III, and V, as well as elastin, proteoglycans, and glycosaminoglycans. Simultaneously, it regulates matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) to balance tissue breakdown and rebuilding.

Gene expression modulation: Genome-wide studies have revealed that GHK-Cu influences the expression of over 4,000 genes — approximately 6% of the human genome. It upregulates genes involved in tissue repair, antioxidant defense, and stem cell function, while downregulating genes associated with inflammation, tissue destruction, and fibrosis.

Anti-inflammatory activity: GHK-Cu suppresses inflammatory cytokines including TNF-alpha, IL-6, and TGF-beta in inflammatory contexts, while supporting appropriate immune responses for tissue repair.

Antioxidant defense: The peptide enhances the production of superoxide dismutase (SOD), a critical antioxidant enzyme, and helps protect cells from oxidative stress damage.

Stem cell support: Research suggests GHK-Cu may support stem cell proliferation and differentiation, contributing to tissue regeneration and repair.

GHK-Cu has one of the most extensive research histories of any cosmetic peptide, with studies dating back to the 1970s:

Wound healing: Multiple human and animal studies demonstrate accelerated wound healing with GHK-Cu application. A controlled clinical study showed that GHK-Cu cream applied to surgical wounds resulted in faster healing and improved cosmetic outcomes compared to controls (Leyden et al., 2002).

Skin aging: Clinical studies have shown that topical GHK-Cu can increase skin thickness, reduce fine lines and wrinkles, improve skin elasticity, and enhance skin clarity. A 12-week facial study demonstrated significant improvements in skin firmness, clarity, and appearance of fine lines (Finkley et al., 2005).

Hair growth: Research indicates GHK-Cu may stimulate hair follicle growth by enlarging follicle size and promoting the anagen (growth) phase of the hair cycle. Studies have shown increased hair density and thickness with topical copper peptide application.

Gene expression: The Broad Institute's Connectivity Map project identified GHK as one of the compounds capable of resetting gene expression patterns associated with aging toward a healthier, younger profile (Campbell et al., 2012).

Based on available research, GHK-Cu has been studied for the following benefits:

• Skin rejuvenation — increased collagen production, reduced wrinkles, improved skin elasticity and firmness
• Wound healing acceleration — faster closure and improved cosmetic outcomes
• Hair growth support — increased follicle size and hair density
• Anti-inflammatory effects — reduced inflammatory signaling in skin and tissues
• Antioxidant protection — enhanced SOD production and oxidative stress defense
• Scar reduction — improved tissue remodeling and reduced fibrosis
• Potential systemic anti-aging — gene expression modulation toward younger patterns

Topical application: GHK-Cu is most commonly used as a topical cream or serum at concentrations of 1-3%. Applied once or twice daily to clean skin, it is considered one of the safest and most well-tolerated cosmetic peptides.

Injectable (subcutaneous): Research protocols using injectable GHK-Cu typically use doses of 1-2 mg daily, administered subcutaneously. Injectable use provides systemic distribution and may offer broader anti-aging benefits beyond skin.

Microneedling combination: Some protocols combine GHK-Cu with microneedling treatments to enhance penetration and stimulate collagen production synergistically.

Duration: Topical GHK-Cu can be used continuously as part of a skincare routine. Injectable protocols are typically run for 4-8 weeks, though specific protocol duration should be discussed with a healthcare provider.

GHK-Cu has an excellent safety profile, particularly in topical form:

Topical: GHK-Cu creams and serums are generally very well tolerated. Rare side effects may include mild skin irritation or redness, particularly in those with sensitive skin or copper sensitivity. Allergic reactions are uncommon.

Injectable: Injection site reactions (redness, mild pain) are the most commonly reported side effects. Systemic side effects are rare at typical research doses.

Contraindications: Individuals with Wilson's disease or other copper metabolism disorders should avoid GHK-Cu. As with all peptides, use during pregnancy or breastfeeding is not recommended without medical guidance.