50 Best Dupes for GHK Cu Copper Peptides Serum by Anai Rui Advanced Copper Peptide Serum 300mg High Purity (99.6%) GHK Cu Mul Sapnne Naturals GHK CU Topical Serum Kit 50ml Azur Skin 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