GHK Cu: The Peptide That Transforms Skin and Tissue Health Calibrate Hydration GHK Cu Copper Peptide Neck & Face Serum 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 Cosmecell GHK CU Super Facial Sunscreen SPF 50 PA++++: The Copper Pept GHK Cu Copper Peptide Serum 1% Conc. Hair and Skin Boost Collagen *BEST VALUE! eBay Australia