The Benefits & Risks of GHK Cu (WATCH BEFORE TAKING) A lot of people asked how I use GHK Cu (copper peptide) with a pen device, so here's a quick tutorial showing exactly how I do it. In this video I show how GHK Cu Copper Peptide Neck & Face Serum Snapklik.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