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 Copper Peptide (GHK Cu) Supplier Cosmetic Ingredient for Formulators Creative Peptides GHK Cu 50mg Copper Tripeptide Research Compound 99% Theoretical study of copper binding to GHK peptide ScienceDirect