The Simple Booster Serum is simple to use and has no complex steps. You have to shake it a little, and the ingredients are activated. Pat a couple of drops onto your clean skin or add them to your daily face cream to boost your vitamin C intake even more. Since it is a waterless formulation, the skin quickly absorbs it and does not leave any sticky or greasy residue; topical 5 Those who plan to put on makeup should apply this before going further because it is lightweight and does not cause any hindrance to makeup application.