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 Copper Peptide (GHK Cu): Clinical Uses, Stability & Compounding Tips 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 GHK Cu vs AHK Cu: Which Copper Peptide Is More Effective? 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 What is GHK Cu? LIVV