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: GHK Cu Copper Peptide Supplement, 120mcg High Purity Supplement for Skin & Hair, Enteric Coated for Maximum Absorption, Vegan & Gluten Free (60 Count) : Health & Household DAILY SPOTLIGHT GHK Cu 200mg from Peptide Partners. GHK Cu is the copper tripeptide biohackers reach for when skin, scalp, and wound repair all need a single upstream signal. Endogenous in healthy human GHK Cu Peptide: What It Does for Body Composition and Metabolic Health GHK Cu 100mg Dosage Protocol PeptideDosages.com