GHK Cu is getting a lot of attention right now, and for good reason. This is not just a skin peptide. It's a copper binding tripeptide with documented effects on gene expression, collagen synthesis, Amazon.com: QUBIT GHK Cu Copper Peptide Supplement for Skin & Hair, Easy to Absorb, Precisely Dosed 90 Vegan Capsules : Health & Household The Effect of the Human Peptide GHK on Gene Expression Relevant to Nervous System Function and Cognitive Decline GHK Cu Peptide Copper Peptide Research Beyond Peptides