Common Ghk Cu Peptide Side Effects What Is GHK Cu? The Copper Peptide That Rejuvenates Skin Amazon.com: Neurogan GHK Cu Copper Peptide Face Cream 4% Peptides for Skin Firmness & Deep Hydration Daily Facial Moisturizer with 2400 MG GHK Cu, 2oz : Beauty & Personal Care 30 ingredients? Or Just the right 2? Most serums use 20 30 ingredients to hide a low concentration of actives. We only use 2 ingredients so we can maximize the GHK Cu. Concentrated. GHK Cu Copper Peptide Collagen Boost & Skin Regeneration Calibrate Hydration Meet your new skincare essential. GHK Cu is a powerful copper peptide that smooths, renews, and revitalizes the skin from within. Say goodbye to dullness and hello to firmer, youthful, glowing skin.