GHK Cu Peptide: What It Does for Body Composition and Metabolic Health GHK Cu (Copper Peptide) is a naturally occurring peptide in the body that binds with copper to support cell repair and renewal. As we age, our levels decrease and thats where supplementation or GHK Cu Copper Peptide Collagen Boost & Skin Regeneration Calibrate Hydration GHK Copper Peptide GHK Cu Tripeptide 1 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