Is it the new niacinamide?<img alt="Ekaterina Klishevnik/Getty Images" src="https://s.yimg.com/ny/api/res/1.2/PpgYK6x3j1USSj0CEcqwdQ--/YXBwaWQ9aGlnaGxhbmRlcjt3PTk2MDtoPTc0Mw--/https://media.zenfs.com/en/real_simple_700/197d96335c7c2744639153a7751aa90d">In the world of skincare ingredients, you have your heavy-hitting big names: the retinoids, alpha hydroxy...