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, GHK Cu (50 MG) Sigma Compounds GHK Cu: The Elegant Copper Peptide for Skin and Scalp Renewal Renew Vitality Molecular crystal structure of the tripeptide GHK Cu. In solution, Download Scientific Diagram