Anybody experiment with GHK Cu peptide yet? Its supposed to help regulate your collagen production. Copper Peptides for Skin: What GHK Cu Does and How It Compares to Retinol GHK Cu as a multifunctional copper peptide: synthesis routes, process engineering and emerging applications Systems Microbiology and Biomanufacturing Springer Nature Link GHK Cu 50 mg Copper Peptide Research Grade PRG