Facial Serums Beauty & Personal Care, Face, G M Collin, Skin Care, Treatments & Masks GM Collin Hydramucine Optimal Serum, 1.0 Fluid Ounce Review by WaxHydra August 6, 2018 No Comments Provides immediate and long lasting moisturization Increases the ability of the skin to recover Optimal hydration levels for smooth and healthy looking skin. More Delightful serum specifically formulated to offer a new 360 degree Hydration Concept.