The Bright and Dark Sides of Reactive Oxygen Species Generated by CopperPeptide Complexes What is GHK Cu Peptides for sale Polaris peptides Buy GHK Cu 50mg & 100mg Copper Tripeptide Koi 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 GHK Cu Engage Peptides