Encyclopedia

GHK-Cu is the copper(II) complex of the naturally occurring tripeptide glycyl-L-histidyl-L-lysine (GHK). It is found endogenously in human plasma, saliva, and urine, with plasma levels declining markedly with age. It is widely used as a topical cosmetic ingredient for skin remodeling and collagen synthesis, where human evidence is strongest; systemic and injectable anti-aging uses are far less validated and not FDA-approved.

GHK was isolated from human plasma by Loren Pickart in 1973 after the observation that plasma from younger donors restored more youthful protein-synthesis behavior in aged liver tissue. The tripeptide (Gly-His-Lys) has a strong affinity for copper(II) and readily forms the GHK-Cu complex. Reported plasma concentrations fall from roughly 200 ng/mL around age 20 to about 80 ng/mL by age 60. The free tripeptide (GHK) has molecular formula C14H24N6O4 and MW ~340.4; the copper complex (GHK-Cu) has formula C14H22CuN6O4 and MW ~403.9. GHK-Cu has the most robust human evidence in topical dermatology and cosmetics, where it is an established ingredient (INCI name Copper Tripeptide-1) studied for collagen and glycosaminoglycan synthesis, skin firmness, and wound repair. Broader systemic claims (neuroprotection, lung repair, anti-cancer gene modulation) derive largely from gene-expression analyses and animal models rather than controlled human trials. As sold for injection by research-chemical vendors, GHK-Cu is unapproved and outside any compliant compounding pathway.

Mechanism of Action

GHK binds copper(II) and is proposed to act as a copper carrier and a signaling molecule that modulates expression of a large number of human genes. Documented activities (largely cell-culture and animal) include stimulation of collagen and glycosaminoglycan synthesis in dermal fibroblasts, promotion of angiogenesis, antioxidant and anti-inflammatory effects, and support of wound closure and tissue remodeling.