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: GHK Cu Peptide for Skin & Hair Facial Serum & Scalp Solution NAD+: Think of it as your body's battery charger. It helps your cells make energy, repair themselves, and stay young. I use it for energy, focus, and slowing down aging. GHK Cu: This Frontiers Exploring the beneficial effects of GHK Cu on an experimental model of colitis and the underlying mechanisms