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 GHK CU Cosmetic for Healthy Skin Aging and Wrinkle Support Pure Prescriptions The Science and Benefits of GHK Cu Peptide: Skincare, Hair Growth, and Beyond What Makes GHK Cu Copper Peptides Blue? GHK CU Color Vitali Skincare 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