GHK Cu Peptide Before and After Results GHK Cu, the copper peptide, is a game changing injectable for radiant skin and so much more Here's what it can do: Boost collagen for smoother, firmer skin Anti aging Cellular Glow Copper Peptide GHK Cu Serum for Face 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