In peptide research, synergy matters. Some compounds may offer greater insight when studied together, and GHK Cu and AHK Cu are two peptides drawing attention for that reason. Different biological pathways Distinct 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 Xray and Solution Structures of CuIIGHK and CuIIDAHK Complexes: Influence on Their Redox Properties Hureau 2011 Chemistry A European Journal Wiley Online Library New Biotinylated GHK and Related Copper(II) Complex: Antioxidant and Antiglycant Properties In Vitro against Neurodegenerative Disorders The Bright and Dark Sides of Reactive Oxygen Species Generated by CopperPeptide Complexes