Over the past year or so, the trending skincare ingredient niacinamide has cropped up everywhere, from beauty magazines to the bottles of lotions and potions sold in stores. There’s a good reason why. Niacinamide is largely considered a holy-grail treatment for many common skin issues, such as premature aging, dull skin, and acne. The ingredient is known to brighten and smooth skin, calm redness and inflammation, reduce hyperp...