Does GHK Cu actually ruin other peptides or is that just bad formulation? Most stacks miss the mark when it comes to stability, but KLOW was designed differently. From pH optimization to independent 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 Wholesale GHK Cu Copper Peptide Tablets for your shop Faire GHK Cu Peptide: What It Does for Body Composition and Metabolic Health