GHK Cu is a naturally occurring copper peptide that declines with age. At 20: abundant. By 60: you have 60% less. What it does: Stimulates collagen and elastin synthesis Promotes wound GHK CU: How to Mix It The Peptide Report 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 YouTube GHK Cu Focal Point Vitality