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 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 GHK Cu (Copper) For Sale (50mg) Core Peptides Introduction GHK Cu is a copper peptide complex formed from the tripeptide glycyl L histidyl L lysine bound to copper. This compound has garnered significant attention in both laboratory and formulation research due to its critical role