The Effect of the Human Peptide GHK on Gene Expression Relevant to Nervous System Function and Cognitive Decline GHK Cu Injections Explained: WThe Peptide Effect Apple Podcasts GHK Cu 100 mg High Purity Copper Peptide Proliven Labs 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