Niacinamide (also known as nicotinamide or 3-pyridinecarboxamide) is the physiologically active form of niacin, or vitamin B3. A deficiency in this essential water-soluble vitamin results in pellagra, a nutritional disease with distinct cutaneous manifestations. Since its discovery and isolation, numerous dermatological therapeutic benefits and mechanisms have been attributed to niacinamide when used topically. These include its role as an anti-acne agent, its ability to upregulate epidermal sphingolipid synthesis, and its enhancement of markers of epidermal differentiation and dermal proliferation—contributing to improved stratum corneum barrier function.
Niacinamide also helps moderate photoimmunosuppression and the development of associated tumors. More recent evidence suggests it can improve the cosmetic appearance of skin by suppressing epidermal melanosome transfer, thereby affecting pigmentation, and by improving surface topography. While the exact mechanisms of these cutaneous effects remain unclear, it is postulated that niacinamide’s function as a precursor to NADH and NADPH—critical nucleotide coenzymes—may allow it to restore local homeostatic balance and support this broad spectrum of skin activity.
Given the dramatic rise in research and usage of niacinamide in recent years, this review explores the current understanding of its mechanisms and dermatological benefits.