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 Peptides Benefits for Anti Aging Skin Rejuvenation How to Use With Micro Infusion GHK Cu Topical Gel Transparent Peptides Understanding Topical GHK Cu Peptide Benefits for Skin Rejuvenation in Maryland Preston's Pharmacy GHK Cu: The Peptide That Transforms Skin and Tissue Health Calibrate Hydration