GHK Cu Copper Peptide Face Tonic for Firmer Looking Skin The GHK Cu copper peptide is one of the most underrated skin repair ingredients out there., Naturally found in the body, it plays a key role in collagen and elastin production, skin healing, and Copper Peptide GHK CU Serum with Hyaluronic Acid and Liberia Ubuy Amazon.com: Skin Perfection Copper Peptide Serum GHK CU 1% for Face & Hair Copper Peptides for Skin, Hair, & Scalp 1% Blue Liquid for Face, Neck, Body, Scalp Multi Use Serum Booster with