A form of vitamin B3 that, at 2-5%, modestly evens blotchy tone, cuts oiliness and supports the skin barrier. Well tolerated by most skin.
Niacinamide is the amide form of vitamin B3. In skin it feeds the NAD cofactors cells use for energy and repair, and it nudges the outer layer to make more ceramides and other barrier lipids. It is water-soluble, stable in most formulas and rarely irritating, which is why it turns up in everything from toners to body lotions.
It is not an exfoliant or a retinoid, so it works slowly: most trials run 4-12 weeks and measure small, real changes — fewer blotches, a less oily T-zone, better-hydrated skin. Serums at 10% or more are common, but the controlled studies used 2-5%, and higher strengths mainly raise the odds of stinging and redness.
Several randomized, vehicle-controlled split-face trials (roughly 20-100 people, 4-12 weeks) found 2-5% niacinamide reduced hyperpigmented spots, red blotchiness, sebum and fine lines. Most were run or funded by one large skincare maker, the effects are modest, and few trials compare it with established drugs. A 2020 Cochrane review rated the acne evidence low quality.
50 women with photoaged skin applied 5% niacinamide to one side of the face and vehicle to the other for 12 weeks; niacinamide reduced fine lines, hyperpigmented spots, red blotchiness and sallowness and improved elasticity. Run by a skincare manufacturer.
Niacinamide did not block melanin production but inhibited pigment transfer to skin cells by 35-68% in a lab model; in 18 people using 5% and 120 people using 2% with sunscreen, it reduced facial hyperpigmentation versus vehicle within 4 weeks.
In 100 Japanese adults, a 2% niacinamide moisturizer lowered sebum excretion rate versus placebo over 4 weeks; in a 6-week split-face study of 30 white adults it reduced surface oil but not sebum excretion rate.
49 trials (3,880 people): azelaic acid is probably less effective than benzoyl peroxide and about as effective as tretinoin for acne; evidence for salicylic acid, nicotinamide and alpha-hydroxy acids was low or very low quality, from small head-to-head trials, and no conclusions were reported for zinc or sulphur.