Young Goose Blue Peptide Spray GHK Cu Peptide Serum Copper Peptide Serum for Tightening, Collagen Boosting & Hydrating Topical GHK Cu with Hyaluronic Acid TikTok Shop Neurogan Health Copper Peptide GHK CU , 120 mcg, 60 Tablets, 0.52 oz (15 g) eBay Copper Peptide (GHK CU) Serum Australian Private Label Skin Care Cellular Cosmetics 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