The copper(II) binding tripeptide GHK, a valuable crystallization and phasing tag for macromolecular crystallography GHK Cu: The Elegant Copper Peptide for Skin and Scalp Renewal Renew Vitality Copper peptide GHK Cu Tripeptide Proteasome Bortezomib, angle, white png PNGEgg Copper peptide (GHK Cu) SIELC Technologies 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 Buy GHK Cu Exceptional 99%+ Purity Third Party COA Included