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 Copper Peptide: Dosage, Before and After Results, and How It Works Perfect B Understanding the Difference Between Glow and GHKCU Peptides GHK Cu Dosage and Protocol: A Medical Provider's Guide to the 30 Day Cycle Perfect B GHK Cu Research Compound Power Peptides