Copper Peptide Serum: Does GHK Cu Really Work for Skin? GHK Cu is one of the most talked about peptides for a reason. Known for its role in skin regeneration, collagen production, and hair support, this copper peptide helps your body do what 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 What is GHK Cu and Why is Everyone Talking About It? GHK Cu (Copper Peptide) is a powerful, naturally occurring compound in the body that plays a key role in skin health