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 Everyone's talking about GHK Cu right now but no one's really explaining it It's a peptide your body already makes and it plays a role in things like skin health, repair, and GHK Cu Copper Peptide Benefits, Uses & Safety Intra V Subcutaneous Injection: What It Is and How to Give One