89030 95 5 GHK Cu Gly His Lys Cu Copper Tripeptide 1; Prezatide copper GHK Cu Hair Growth The naturally occurring peptide GHK reverses age related fibrosis by modulating myofibroblast function He Aging Pathobiology and Therapeutics Defy GHK Cu (glycyl L histidyl L lysine) is a naturally occurring copper binding peptide found in human plasma. As levels decline with age, so may its support of the biological processes involved in collagen production, skin Copper, Collagen, and Controversy: Inside the GHK Cu Buzz