How to Ensure the Stability and Efficacy of GHK Cu in Skincare Products? Knowledge Bioway Organic Copper Peptide Serum with 1% GHK Cu peptide, Argireline and Matrixyl 3000 Copper Peptide (GHK Cu) 2% Recovery Serum How to look much younger within a year GHK Cu is one of the most studied skin peptides on the planet, it stimulates collagen production, improves firmness, and helps skin recover from damage.