GHK Cu Peptide Therapy: The Definitive Clinical Guide to Gene Modulation, Protocols, and Efficacy 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 Copper Peptides Serum for Face 2% GHK CU & 4% EGF Seraphime Topical or SubQ GHK Cu? Same molecule. Very different purposes. Topical you apply it on your skin. Think of it as feeding your skin from the outside. In a 12 week study of 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