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, GHK Cu Copper Peptide Serum 1% Black Tie Health GHK Cu 50mg Copper Peptide Research Spartan Peptides Your copper peptide product should be this exact blue. If it isn't, you already have your answer. GHK Cu is blue because of coordination chemistry, not dye. The Cu ion at the center