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 Is Less More? Influence of the Coordination Geometry of Copper(II) Picolinate Chelate Complexes on Metabolic Stability Inorganic Chemistry Buy GHK Cu 50mg & 100mg Copper Tripeptide Koi Peptides Theoretical study of copper binding to GHK peptide ScienceDirect Copper Peptide (GHK Cu) Supplier Cosmetic Ingredient for Formulators Creative Peptides