The Best Peptides For Glowing Skin: From GHK Cu To TB 500 Copper Peptides GHK Cu Beef Tallow for Skin: Blue Balm with Methylene Blue, Manuka Honey & Vitamin E Natural Face and Body Moisturizer for Mature, Dry & Delicate Skin 2oz The Science Behind the Benefits of GHK Cu UK SARMS 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