A GHK Cu face serum appears blue because the active ingredient, GHK Cu (copper peptide), is naturally a blue colored powder, meaning its inherent color transfers to the serum when mixed in; this blue hue 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 GHK Cu: The Peptide That Supports Healthy Aging GHK Cu (copper peptide) is naturally occurring in the body and plays a role in supporting skin health, collagen production, and tissue repair. As GHK CU Crescent Chems Research