Amazon.com: GHK Cu Copper Peptide Serum Anti Aging Face Serum for Skin Firming, Wrinkle Reduction, Hydration & Collagen Boosting, 30ml(1 fl oz) : Beauty & Personal Care GHK Cu Topical Cream 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 Therapy: The Definitive Clinical Guide to Gene Modulation, Protocols, and Efficacy 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 50mg 10mL Vial: Automatic Refills Celia Health