Advanced GHK Cu Face Cream 2400mg 4% Firmer Skin Neurogan Neurogan Health Not all copper peptide serums are formulated the same Before you buy one, make sure you're actually getting pure GHK Cu at the right concentration not just a diluted blend. We spent 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) Provider Supervised Therapy IV Glow Bar