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 Locations and Hours Gold Coast Federal Credit Union PHOTOS: Gil Hanse designed West Palm Golf Park to open to public 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