inorganic chemistry Why do copper (II) complexes contain so many valence electrons? Chemistry Stack Exchange GHK Cu Copper Tripeptide 1 Research Reagent Copper Peptide GHK Cu for Sale Stanford Advanced Materials The copper(II) binding tripeptide GHK, a valuable crystallization and phasing tag for macromolecular crystallography 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 peptide GHK Cu Wikipedia