GHK Cu (10 mg, 50 mg, 100 mg) COA verified peptide Nootropix Whitening GHK CU Copper Peptide Serum for All Skin Types 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 Peptide Hormone Replacement Therapy Los Angeles Peptide GHK CU Cream Concierge MD 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