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 Peptide Regenerating Serum for Glowing Skin and Hair The glycyl l histidyl l lysine Cu2+ tripeptide complex attenuates lung inflammation and fibrosis in silicosis by targeting peroxiredoxin 6 ScienceDirect Why Collagen Loss Accelerates After 40: The Role of GHK Cu in Menopaus Pure & Cimple