Copper Tripeptide (GHK Cu) for Advanced Skincare & Haircare Formulatio Copper peptides like GHK Cu work by sending signals to your skin to repair, regenerate, and produce collagen. It's not about instant results, it's about improving how your skin functions over time. Dr. 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 is not Botox. It does not freeze a single muscle. It works because it works at the matrix level. GHK Cu stimulates collagen and glycosaminoglycan synthesis, modulates the matrix metalloproteinases that govern