Niacinamide is one of those ingredients that you always hear about, but you should own more products that contain it. The thing is, if you have acne-prone skin, it's key. It flushes out pores to prevent future breakouts and in the case of The Ordinary Niacinamide 10% + Zinc 1% ($6) uses niacinamide in tandem with zinc PCA to control sebum production.