GHK CU Before and After Pictures Topical GHK Cu Skin Results, Face Serum Reviews & Photo Results Neurogan Health GHK Cu Peptide Therapy: The Definitive Clinical Guide to Gene Modulation, Protocols, and Efficacy 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: 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