GHK Cu Peptide Therapy: The Definitive Clinical Guide to Gene Modulation, Protocols, and Efficacy The GHK Cu pen works. But needles at home were never the answer. We took the same clinically backed copper peptide complex and put it into a serum you can use in 30 seconds, Peptides: The growing W E L L N E S S trend that everyone is talking about! You may have heard about BPC 157 and GHK Cu two peptides gaining attention in GHK Cu vs NAD+: Which Longevity Peptide Should You Take or Stack?