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 Copper Peptide Ghk Cu 99% Skin Care Ghk Cu 50mg 100mg vials Cosmetic Ingredient GHK GHK CU and blue copper Copper Peptide Ghk Cu Powder Top Grade Cosmetics Ingredient Lyophilized Powder Peptide Ghk Cu Copper Peptide C14h24n6o4 Lyophilized and Petides