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. Why Collagen Loss Accelerates After 40: The Role of GHK Cu in Menopaus Pure & Cimple Copper Peptide Regenerating Serum for Glowing Skin and Hair Regenerative properties of the NL GHK Cu peptide and skin appearance Synthagen PL 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