GHK Cu Peptide: What It Does for Body Composition and Metabolic Health First time getting GHK Cu. Does this look ok? Not sure if this is how its supposed to look. : r PeptidePathways 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 Glow Peptide Protocol GHK Cu, BPC 157, TB 500 Neurogan Health