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 Understanding Glutathione Deficiency Invigor Medical Who Offers Glutathione IV Therapy in San Antonio, TX? 1% GHK CU solution: is this applied directly on skin or diluted further? : r DIYaesthetics Close Blue Copper Peptides Ghk cu Powder Stock Photo 2682985977 Shutterstock