Not all copper peptide serums are formulated the same Before you buy one, make sure you're actually getting pure GHK Cu at the right concentration not just a diluted blend. We spent Pierce Glutathione Superflow Agarose 10 mL Buy Online Thermo Scientific GHK Cu Copper Peptide Skincare Bundle RegenMed Direct Intense Copper Binding GHK Cu 5% +Palmitoyl Oligopeptide 0.3% Repair S Chebo Clinic superPeptide 1% GHK Copper Peptide Serum Pure & Cimple