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 Synergy of GHKCu and hyaluronic acid on collagen IV upregulation via fibroblast and exvivo skin tests Jiang 2023 Journal of Cosmetic Dermatology Wiley Online Library Top 9 GHK Cu Benefits for Skin, Hair, and Anti Aging 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 Revitalize Your Skin: The Benefits of Copper Peptide for Youthful Glow By age 30, your skin produces about 25% less collagen. By 40, that number can reach 40%. This decline affects more than just how your skin looks. It changes how it heals,