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 Theoretical study of copper binding to GHK peptide ScienceDirect GHK Cu 50mg PeptideX Research GHK Cu 50 MG US Precision 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