Cu(II) Binding to the Peptide Ala His His, a Chimera of the Canonical Cu(II) Binding Motifs Xxx His and Xxx Zzz His Inorganic Chemistry Buy GHKCu Copper Peptide Research Solution Lab Use Buy GHK Cu 50mg 99% Purity Made in USA Peptide Buy GHK Cu Peptide 99%+ Purity GHK Cu for Research 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