GHK Cu as a multifunctional copper peptide: synthesis routes, process engineering and emerging applications Systems Microbiology and Biomanufacturing Springer Nature Link 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 GHK Cu 50mg Copper Peptide Research Spartan Peptides GHK Cu: The Elegant Copper Peptide for Skin and Scalp Renewal Renew Vitality Theoretical study of copper binding to GHK peptide ScienceDirect GHK Cu