How to Measure and Inject GHK Cu (Copper Peptide for Skin and Tissue Repair) YouTube GHK CU GHKCu (glycyl L histidyl L lysine copper) is a naturally occurring copper peptide found in the human body, particularly in plasma, saliva, and urine. It plays a key role in skin regeneration by promoting 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 GHK CU Copper Peptide, Hair & Scalp Serum, 2 oz (60 ml)