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 Frontiers Exploring the beneficial effects of GHK Cu on an experimental model of colitis and the underlying mechanisms Copper Peptide Regenerating Serum for Glowing Skin and Hair GHK Cu Peptide Serum: Copper Peptides for Skin Firmness Mythos Mythos Skincare