The Effect of the Human Peptide GHK on Gene Expression Relevant to Nervous System Function and Cognitive Decline GHK Cu might be trending, but it's not new. Before you inject yourself with this viral peptide, consider this. This copper peptide has been studied for years in skin repair and collagen signalling, Is GHK Cu a Promising Path to Better Healthspan and Longevity? by Peter Marino, M.S. CHC CPT Medium Copper peptides explained what are the differences between copper peptides and GHK CU peptides? What they actually do for the skin in terms of repair and collagen, and what you can and cant mix