Squalane + Copper Peptide (GHK Cu) Rapid Plumping Serum Advanced GHK Cu Face Cream 2400mg 4% Firmer Skin Neurogan Neurogan Health Not all Copper Peptides are created equal If you've tried copper peptides before and saw no change, here is why: Concentration and Stability. Most serums use a diluted solution that barely scratches The first order degradation profiles of GHK Cu in various medium stored Download Scientific Diagram