People are turning themselves into lab rats': the injectable peptides craze sweeping the US Well actually The Guardian GHK Cu is one of the most talked about peptides in aesthetics right now. But how much of what you have heard about it is actually true? Copper peptide, known as GHK Cu, has Is GHK Cu Legal? FDA Approved Peptides Neurogan Health 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