One of the questions we often receive about our products is: Why is the GHK Cu Repairing Serum stored in two part packaging? GHK Cu is an unstable ingredient that can slowly lose its effectiveness Elixxis Health Systems: Clinical Grade Peptides. Trusted Purity. Glow Peptide AH Clinics I've had @sumanurica in my routine for almost a year now, so adding the new GHK Cu Repairing Serum felt like the perfect next step It's lightweight, calming and layers beautifully, especially