GHK Cu for Hair Growth? It Works But Only If You Do It Right. Everyones talking about GHK Cu, but heres the catch most serums never make it past your scalp barrier. If the formulas too weak, it GHK Cu (Copper Peptide) Provider Supervised Therapy IV Glow Bar Copper Peptide Serum with 1% GHK Cu peptide, Argireline and Matrixyl 3000 GHK Cu Plus Copper Peptide Face Cream Peptide Warehouse Canada