The Ultimate L Glutathione Supplement Guide 2022: Uses, Benefits, Side Effects & Dosing A GHK Cu face serum appears blue because the active ingredient, GHK Cu (copper peptide), is naturally a blue colored powder, meaning its inherent color transfers to the serum when mixed in; this blue hue Dermicu GHK Cu Facial Serum Bacteriostaticwater.com GHK Cu Peptides Level Up Your Look Bundle Aseir Custom Liposomal Glutathione Uses and Benefits BodyBio 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