Copper Peptide (GHK-Cu)
A naturally occurring tripeptide (glycyl-L-histidyl-L-lysine) complexed with copper that declines with age. GHK-Cu has been studied for wound healing, collagen stimulation, and anti-inflammatory properties. It is one of the most researched cosmetic peptides, available in topical skincare products.
Technical Context
GHK (glycyl-L-histidyl-L-lysine) is a naturally occurring human tripeptide with high affinity for copper(II) ions (binding constant ~10^-16 M). Plasma GHK levels decrease with age: approximately 200 ng/mL at age 20 → approximately 80 ng/mL at age 60. Proposed mechanisms of action: stimulation of collagen and glycosaminoglycan synthesis (via activation of fibroblasts and decoration synthesis), promotion of angiogenesis, anti-inflammatory effects (suppression of TNF-α, IL-6), antioxidant activity (copper is a cofactor for superoxide dismutase), attraction of immune cells to wound sites, and stimulation of nerve growth. The copper delivery function is significant — copper is essential for lysyl oxidase (collagen crosslinking), superoxide dismutase (antioxidant defence), and cytochrome c oxidase (mitochondrial energy production). Clinical evidence: published studies show wound healing acceleration in animal models and improved skin quality in small human trials, but large RCTs are lacking.