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 Copper tripeptide (GHK Cu; Copper Glycyl histidine tripeptide) CAS 89030 95 5 AbMole BioScience Copper tripeptide Price Copperbiomolecule complexes in the gas phase. The ternary way Tureek 2007 Mass Spectrometry Reviews Wiley Online Library GHK CU (50mg) Nordsci