GHK Cu Copper Peptide Skin & Healing Beverly Hills What is GHK Cu and Why is Everyone Talking About It? GHK Cu (Copper Peptide) is a powerful, naturally occurring compound in the body that plays a key role in skin health How long does it take GHK Cu to work? Entera Skincare Copper peptide questions we get asked all the time How often should you use it? Do you need to avoid the sun? If you're new, start once daily (evenings are great),