GHK-Cu

GHK (glycyl-L-histidyl-L-lysine) is a human peptide present in plasma, saliva, and urine that declines with age. ^[1] It has a high affinity for copper ions and easily forms a copper complex, GHK-Cu, that accelerates wound healing and skin repair. ^[1] The human tripeptide GHK was discovered in 1973 as an activity in human albumin that caused old human liver tissue to synthesize proteins like younger tissue. ^[2]

GHK stimulates the synthesis of collagen, elastin, and glycosaminoglycans, supports the function of dermal fibroblasts, and stimulates blood vessel and nerve outgrowth. ^[3] GHK-Cu exerts anti-inflammatory actions, including suppression of free radicals and of transforming growth factor beta-1 and tumor necrosis factor alpha, while increasing superoxide dismutase, and it attracts repair cells such as macrophages and capillary cells to the site of an injury. ^[4] GHK is reported to be capable of up- and downregulating at least 4,000 human genes, essentially resetting DNA to a healthier state. ^[1]

GHK-Cu stimulates wound healing in numerous animal models and in humans, and induces systemic wound healing in rats, mice, and pigs. ^[1] Controlled studies on aged skin have demonstrated that GHK-Cu tightens skin, improves elasticity and firmness, and reduces fine lines, wrinkles, photodamage, and hyperpigmentation. ^[4] Despite wide use of GHK-Cu in anti-wrinkle cosmetic products, there is a surprising absence of clinical studies using it, with the anti-wrinkle conclusion resting largely on cellular studies. ^[5] In an orthopaedic and sports-medicine review, GHK-Cu showed promise in wound healing and anti-inflammatory effects but no clinical data supported its use for musculoskeletal conditions. ^[6]

GHK-Cu has multiple biological actions that appear health-positive, including collagen synthesis, DNA repair, anti-inflammatory actions, and suppression of molecules thought to accelerate the diseases of aging such as NF-kappaB. ^[3] Because of its antioxidant, anti-inflammatory, and copper-balance-restoring properties, GHK-Cu has been proposed as a possible therapeutic agent against age-associated neurodegeneration and cognitive decline, a use that remains a proposal rather than an established indication. ^[2] A limitation for topical and cosmetic use is that GHK-Cu is a fairly hydrophilic compound with limited permeation through the lipophilic stratum corneum. ^[7]