GHK Cu: The Peptide That Transforms Skin and Tissue Health Calibrate Hydration GHK Cu may Prevent Oxidative Stress in Skin by Regulating Copper and Modifying Expression of Numerous Antioxidant Genes Why Collagen Loss Accelerates After 40: The Role of GHK Cu in Menopaus Pure & Cimple GHK Cu is a naturally occurring tripeptide in human plasma. Levels average 200 ng ml at age 20 and drop to 80 ng ml by age 60 (Pickart et al., 2020). That decline tracks with Molecular structure of the tripeptide GHK Cu. In solution lysine Download Scientific Diagram