Neurogan Health, Copper Peptide GHK CU, 120 mcg, 60 Tablets iHerb GHK Cu is one of the most talked about peptides in aesthetics right now. But how much of what you have heard about it is actually true? Copper peptide, known as GHK Cu, has 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: NAD+ vs Peptides: The Differences, Explained