GHK-Cu

GHK-Cu is a naturally occurring copper-binding tripeptide (glycyl-L-histidyl-L-lysine complexed with copper II) first isolated from human plasma in 1973. Endogenous GHK plasma levels decline with age, falling from roughly 200 ng/mL at age 20 to about 80 ng/mL by age 60, a drop that researchers have linked to reduced regenerative capacity. It is best known as an ingredient in anti-aging skincare under the cosmetic name Copper Tripeptide-1. The strongest human evidence is topical and cosmetic: small placebo-controlled facial-cream and eye-cream trials report increased collagen, improved skin density and thickness, and reductions in fine lines and photodamage over roughly 12 weeks. Much of the broader literature on tissue, nerve and systemic effects is preclinical (animal and in-vitro) or based on gene-expression profiling. Despite popularity in research-peptide communities for injectable and reconstituted use, there is no established systemic dosing protocol from controlled human trials. Injectable use is anecdotal and carries different risk considerations than topical use, including copper handling. GHK-Cu products sold as research material are not approved for human consumption.