GHK Cu 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 50 mg Copper Peptide Research Grade PRG GHK Cu 50mg High Purity Research Peptide Copper peptide GHK Cu Tripeptide Proteasome Bortezomib, angle, white png PNGEgg Theoretical study of copper binding to GHK peptide ScienceDirect