GHK CU 100mg 99%+ Purity, COA Verified GHK Cu Youthful Skin, Healthy Cells, Vibrant You. Copper Peptide Serum for Dull & Mature Skin VALNCIA Close Blue Copper Peptides Ghk cu Powder Stock Photo 2682985977 Shutterstock ZenLabs Resources & Tools 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