GHK Cu Peptide: Hair Regrowth for Thinning & Alopecia 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 11 BEFORE & AFTER ideas copper peptides, crepey skin, eyebrow lift 12 weeks in, and my skin has NEVER looked better! GHK peptides are doing their thing., Alright, I need to give you an updateit's been 12 weeks since I started using GHK peptides from Transcend, and