Skin Perfection GHK Cu Copper Peptide Serum Booster, 1 Percent Blue Liquid For Face, Neck, Body, Hair, And Scalp, 0.5 oz Walmart.com Copper Peptide Skincare Routine: How to Layer Peptides Glimmer Goddess Glutathione Uses, Benefits, Side Effects And Medicines 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