This is a wonderful niacinamide serum for sensitive or acne prone skin. So many popular niacinamide serums have 10% niacinamide which can be incredibly irritating on skin. In the case of niacinamide, a higher percentage does not equal better and many studies have shown the sweet spot on efficacy is around 5% (which is what this serum has). Worked wonders on my skin!! I was gifted an extra otherwise would keep for myself! Comes NIB & include 2 glossier samples💕 Bundle with other items from my closet and save $$!! More Glossier items to also browse from⭐️