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 Before and After Pictures Topical GHK Cu Skin Results, Face Serum Reviews & Photo Results Neurogan Health GHK Cu Peptide: What It Does for Body Composition and Metabolic Health 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