GHK Cu may Prevent Oxidative Stress in Skin by Regulating Copper and Modifying Expression of Numerous Antioxidant Genes GHK CU Apollo Peptide Sciences The Effect of the Human Peptide GHK on Gene Expression Relevant to Nervous System Function and Cognitive Decline GHK Cu is a copper peptide known for supporting skin repair, collagen production, and overall tissue healing., Traditionally, its taken as an injection but that can come with irritation, bruising, or