Definitive Guide on Peptides for Skin and Hair Care Infusion Clinic ABQ The Effect of the Human Peptide GHK on Gene Expression Relevant to Nervous System Function and Cognitive Decline GHK Cu vs AnagenX: Which Peptide Approach Supports Hair Growth Best? GHK Cu is a copper peptide that plays a role in tissue repair and collagen synthesis. The result: improved texture, firmness, and overall skin quality.