SumaNurica GHK Cu Repairing Serum BRAND NEW, SEALED Restorative Skincare eBay 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 Growth Hormone and Metabolic Homeostasis EMJ Reviews GHK Cu Hair & Scalp Serum 2400mg 4% Less Shedding Neurogan Neurogan Health Ive had @sumanurica in my routine for almost a year now, so adding the new GHK Cu Repairing Serum felt like the perfect next step , Its lightweight, calming and layers beautifully, especially on Growth Hormone Negative Feedback Loop BioRender Science Templates