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 Fitish Most people don't know GHK Cu by name. Their face does. It's the peptide your body uses to signal collagen production, repair tissue, Instagram Resetting Skin Genome Back to Health Naturally with GHK Springer Nature Link GHK Cu Copper Peptide Injections: Advanced Skin Rejuvenation