GHK-Cu (Glycyl-L-Histidyl-L-Lysine Copper) is a naturally occurring copper-binding tripeptide found in human plasma, saliva, and urine. Plasma levels of GHK-Cu decline significantly with age (from approximately 200 ng/mL at age 20 to 80 ng/mL by age 60), and this decline correlates with reduced regenerative capacity. GHK-Cu is one of the most extensively studied peptides for skin rejuvenation, wound healing, and anti-aging applications. It has the remarkable ability to reset gene expression patterns in aged tissue toward a healthier, younger profile. Beyond cosmetic applications, GHK-Cu promotes tissue remodeling, reduces inflammation, and supports overall connective tissue health.
Notes
GHK-Cu was discovered by Dr. Loren Pickart in the 1970s. It is one of the most studied peptides in dermatology and wound healing. Multiple topical products containing GHK-Cu are commercially available. Injectable GHK-Cu is sold as a research peptide.
GHK-Cu exerts its effects through multiple mechanisms. The copper ion is essential for the activity of numerous enzymes involved in tissue repair, including lysyl oxidase (collagen cross-linking), superoxide dismutase (antioxidant defense), and tyrosinase (melanin synthesis). GHK-Cu stimulates collagen I, III, and V synthesis, increases elastin production, promotes glycosaminoglycan (GAG) synthesis including decorin, and activates matrix metalloproteinases (MMPs) for healthy tissue remodeling. Gene expression studies show that GHK-Cu modulates over 4,000 human genes, broadly resetting expression toward a healthier state: upregulating genes involved in repair and antioxidant defense while downregulating genes associated with inflammation and tissue destruction.
GHK-Cu is a small tripeptide with rapid absorption after subcutaneous injection. Peak plasma levels are reached within 30-60 minutes. While the plasma half-life is short (2-4 hours), the biological effects persist longer because: (1) copper is deposited into tissues where it continues to catalyze enzymatic activity, and (2) gene expression changes initiated by GHK-Cu persist beyond the peptide's plasma presence. Topical penetration is limited but enhanced by microneedling or liposomal formulations. Metabolism is through normal proteolytic degradation.
Typical Dose
Subcutaneous injection: 1-3 mg per day (most common: 1-2 mg daily). Topical: applied as a cream or serum (typically 0.01-0.1% concentration) once or twice daily. For wound healing: 1-2 mg injected near the wound site. Cycles typically run 4-12 weeks.
Frequency
Daily for injection (once or twice daily). Twice daily for topical application (morning and evening).
Administration
Subcutaneous injection for systemic anti-aging and healing effects. Topical application (creams, serums) for skin-specific benefits. Can also be applied via microneedling for enhanced dermal penetration. Injection is the most effective route for systemic benefits.
Half-Life
2-4 hours (plasma half-life); tissue effects persist much longer due to copper deposition and gene expression changes
Contraindications
No PCT required. GHK-Cu has no effect on the hormonal system. It can be cycled (8-12 weeks on, 4 weeks off) or used continuously at lower maintenance doses.