Copper Peptides for Skin: What GHK Cu Does and How It Compares to Retinol Copper Peptides vs Retinol: Do You Need Both? Nubeean Noosa Copper Peptide Duo GHK Cu Anti Aging Serum & Moisturizer Copper Peptide (GHK Cu) 2% Recovery Serum Most skincare stays on the surface., GHK Cu works deepersupporting your skin at the cellular level without the irritation cycle of retinol., No redness., No downtime., Just real support where it GHK Cu Peptides Serum TryDeloura