GHK Cu Peptide Serum Copper Peptide Serum for Tightening, Collagen Boosting & Hydrating Topical GHK Cu with Hyaluronic Acid TikTok Shop 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 GHK cu Cosmetic Topical 5x 1g Ampules NEXAPH GHK Cu Peptide Serum 30 ml, Copper Peptide Serum with Hyaluronic Acid for Tightening, Collagen Boosting