GHK Cu Dosage and Protocol: A Medical Provider's Guide to the 30 Day Cycle Perfect B 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 GHK Cu Peptide: What It Does for Body Composition and Metabolic Health GHK Cu Copper Peptide: Dosage, Before and After Results, and How It Works Perfect B GHK Cu Peptide for Skin & Hair Facial Serum & Scalp Solution