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 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 Glow Peptide AH Clinics SumaNurica GHK Cu Repairing Serum Face Oil with Copper and Tripeptide 1 Nourishes Skin Vegan, Fragrance Free For Sensitive Skin 3 x 0.33 oz : Buy Online at Best Elixxis Health Systems: Clinical Grade Peptides. Trusted Purity.