GHK Cu Peptide: What It Does for Body Composition and Metabolic Health NAD plus 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 Can GHK Cu Be Taken Orally? Oral GHK Cu Bioavailability, Tablets & Copper Peptide Safety Neurogan Health