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 Face Serum 1200MG Lab Tested & High Potency Neurogan Health 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 GHK Cu Peptides: Unlocking the Copper Peptide Revolution in Skin Care