GHK Cu (50 MG) Sigma Compounds GHK cu is a copper peptide. It's great for skin, especially when you combine it with other things. My favorite is DMSO and derma rolling. My first experience with copper peptides was Procytes GHK cu is a copper peptide. It's great for skin, especially when you combine it with other things. My favorite is DMSO and derma rolling. My first experience with copper peptides was Procytes GHK Cu Uncovered A Comprehensive Guide to Anti Aging, Wound Healing, and Biohacking Protocols: Unleashing Peptide Science for Collagen Regeneration and Athletic Recovery (Peptide & SARMs Guides): Pierce, Gavin: 9798280350304: Amazon.com: Books Neurogan Health, GHK Cu Copper Peptide, Hair & Scalp Serum