GHK Cu Topical vs Injection Which is the Better Copper Peptide Form? Should Bodybuilders Take GHK Cu? Neurogan Health The Effect of the Human Peptide GHK on Gene Expression Relevant to Nervous System Function and Cognitive Decline GHK Cu: My secret weapon for skin, hair, and healing, I use it two ways topical cream for my face, and subQ injections 3x a week., It boosts collagen, tightens skin, helps hair grow, and even