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 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 50mg Copper Peptide Research Spartan Peptides Copper Peptide (GHK Cu) Supplier Cosmetic Ingredient for Formulators Creative Peptides