How to Use GHK Cu Repairing Serum SumaNurica Did you know that Tretinoin can damage GHK Copper Peptides?. If you use Tret at night, save your GHK Lux for the morning. , Get the full safety guide on our YouTube Channel!, #platinum_skin_care GHK Cu Peptide: What It Does for Body Composition and Metabolic Health Why is the injection site painful after administering GHK Cu (Glycyl L Histidyl L Lysine Copper) 2mg mixed with normal saline? If your GHK injection site gets irritated try this , 1. Dilute it by adding more water to the syringe , 2. Let it sit until it reaches room temperature , Also, make sure youre rotating injection