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 What is GHK Cu Collagen and Elastin Support Neurogan Health GHK Cu 50 mg Copper Peptide Research Grade PRG Molecular crystal structure of the tripeptide GHK Cu. In solution, Download Scientific Diagram Is Less More? Influence of the Coordination Geometry of Copper(II) Picolinate Chelate Complexes on Metabolic Stability Inorganic Chemistry