Four reasons this serum belongs in your routine. GHK Cu Peptides that firm and support collagen renewal. Barrier support to keep your skin healthy and resilient. No injection. No needles. No clinic visit. Everyone seems to be talking about GHK Cu right now but most people still don't understand what it actually does. GHK Cu is a naturally occurring copper binding peptide that has been studied for its GHK Cu Peptide: What It Does for Body Composition and Metabolic Health GHK Cu (50 MG) Sigma Compounds