GHK Cu Copper Peptide Neck & Face Serum NAD+ and GHK Cu aren't interchangeable! They're complementary One restores what's happening beneath the surface: cellular energy, mental clarity, vitality that lasts beyond a caffeine rush. The other rebuilds what you see: 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 KPV NAD+ GHK Cu Peptide Patch Medical Imaging and Therapeutics