Niacinamide Vitamin B3 works for Water Loss Prevention at 2%?? Acne at 4%?? and Skin Whitening at 5%.</br>Niacinamide is also used to treat acne?? and in an 8 week study in which patients were treated with a 4% concentration Niacinamide gel?? 82% of patients treated with Niacinamide were considered improved.</