Azelaic acid, niacinamide, or both? Dermatologists break it down.
Siena Gagliano is the Beauty Editor at Marie Claire. She specializes in the beauty and fashion industries, covering topics such as makeup, skincare, hair care, and wellness programs, with a focus on reported features and expert-backed shopping roundups. Siena's work has been featured in notable publications including Yahoo News, Well+Good, Bustle, Allure Magazine, Glamour Us, Cosmopolitan, AOL, Inc., and MSN.












