ghk cu hair growth randomized controlled trial Say hello to your skin's new BFF GHK Cu is a powerful peptide that supports collagen production, speeds healing, improves hair growth, and helps fight GHK Cu Peptide: Hair Regrowth for Thinning & Alopecia 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 Absolute GHK cu Stem Cells & Peptide Hair Growth Serum and Shampoo MTS Mall of California