GHK CU Crescent Chems Research Copper Peptide (GHK Cu) Serum 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 Peptide (50mg) Advanced Skin Rejuvenation & Healing Support GHK Cu as a multifunctional copper peptide: synthesis routes, process engineering and emerging applications Systems Microbiology and Biomanufacturing Springer Nature Link