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 repair, and GHK Cu may Prevent Oxidative Stress in Skin by Regulating Copper and Modifying Expression of Numerous Antioxidant Genes Copper Peptides Elmhurst IL Chicago Accelerated Aesthetics Ozark Have you heard of GHK Cu the copper peptide your body is already making? GHK Cu (Glycyl L Histidyl L Lysine Copper) is a naturally occurring tripeptide found in human plasma, saliva, and urine.