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 (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 Amazon.com : Amino Innovations Peptide Hair Serum for Hair Growth Thicker, Fuller, and Stronger with Copper Tripeptide 1, Zinc Thymulin & PTD DBM DMSO Enhanced Formula for Scalp Health and Resilience : GHK Cu 50mg 5 Vials Us Chem Labs GHK Cu DrBrainRX