Niacinamide and nicotinic acid are derivatives of vitamin B3. There is a handful of studies showing they can be helpful for improving the appearance of acne, most likely for their anti-inflammatory capacity. Many cosmetics companies are beginning to include these two ingredients in the products they’re aiming at blemish-prone skin as well as in “anti-wrinkle” products. Especially when they’re part of a great skin-care routine that also includes either an over-the-counter benzoyl peroxide antibacterial and salicylic acid exfoliant, or a prescription topical antibiotic with benzoyl peroxide, they contribute to a powerful combination of products to combat the events taking place in skin that is fomenting acne.
(Sources: Journal of Cosmetic Laser Therapy, June 2006, pages 96-101; and Journal of Cosmetic Dermatology, April 2004, pages 88-93.)