Copper Peptide | GHK-Cu | Skin SerumCopper Peptide Serum 0. 5% and 1% A copper peptide serum with nothing to hide behind just a quality active in a clean, stable base. GHK Cu is a naturally occurring peptide your body already knows in a minimal, stability focused formulation. No fragrance, no fillers, no compromises on potency. Over 50 years of research. Over 4,000 genes influenced. A naturally occurring peptide that declines with age now in a clean Australian made serum designed to