GHK Cu Copper Peptide Hair & Scalp Serum Copper Peptides Serum for Face 2% Copper Peptide with 4% Epidermal Growth Factor (EGF Serum) Niacinamide Ceramides Squalane & Hyaluronic Acid Multi 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 ZnO nanoparticles modified with biomaterial GHK Cu as electron transport layer to fabricate highly efficient inverted polymer solar cells ScienceDirect Young Goose Blue Peptide Spray