HealthyDerm GHK CU Peptide Beef Tallow for Skin: Blue Balm with Methylene Blue, Manuka Honey & Amazon.com: Skin Perfection Copper Peptide Serum GHK CU 1% for Face & Hair Copper Peptides for Skin, Hair, & Scalp 1% Blue Liquid for Face, Neck, Body, Scalp Multi Use Serum Booster with BLUE Copper Peptide GHK CU Serum with Hyaluronic Acid Anti Wrinkle Assortment eBay Ward What make blue? . The blue color of GHK Cu is due to the copper ion mineral bound with the peptide. The binding occurs through the donation of electrons