Does niacinamide actually work for skin?

The short answer for everyday skin

For cosmetic use, topical niacinamide is the form that matters, and the evidence is decent but not dramatic. A 2021 narrative review found that topical nicotinamide, alone or combined with other actives, reduced skin aging and hyperpigmentation in clinical trials and was well tolerated 2021 nicotinamide review.

That review is not a systematic review, and it concluded there is no convincing evidence for a single molecular target. For the ingredient basics, read our niacinamide explainer.

Dark spots and uneven tone: the strongest signal

This is where the trials look most consistent. A P&G-authored study in JAAD found that 2% and 5% niacinamide products reduced facial hyperpigmented spots in a dose-dependent way Hakozaki 2005 JAAD study03457-7/fulltext).

The catch is that the effect reversed after use stopped. Treat it as maintenance rather than a one-time fix, and factor in the industry authorship when you weigh the result.

Acne and oil: promising, but thin

The acne data are small and messy. In an 8-week double-blind trial, 5% nicotinamide gel was compared with 2% clindamycin gel, and physician-rated improvement was 82% versus 68%. That gap was not statistically significant (P = 0.19), and the authors concluded non-inferiority Shahmoradi 2013 acne trial.

The same paper is internally inconsistent on sample size and gel strength, so we treat it as low-confidence. On oil, a systematic review of topical acne treatments cited one trial of 41 participants where niacinamide reduced sebum production, and it was not the review's focus acne treatment systematic review.

Sun stress and barrier: a controlled study, with a caveat

The most controlled human study we found enrolled 44 women with Fitzpatrick II to III skin. Two weeks of 5% niacinamide before and after UV exposure reduced UV-induced redness compared with vehicle and untreated skin. It also reduced barrier disruption measured by TEWL and an inflammatory cytokine ratio JAAD UV erythema study01394-1/abstract).

Where niacinamide is not the answer

Oral and high-dose uses are a separate category. A 2024 JAAD update describes 1.5 g a day as a treatment dose for inflammatory skin disease and 500 mg twice daily as a chemoprevention dose for high-risk patients. It reports good tolerability but no proven skin-cancer prevention benefit in healthy people without prior non-melanoma skin cancer JAAD nicotinamide update02737-3/abstract).

For actinic keratosis, a small trial of 26 patients with 95 lesions found 5% fluorouracil cream outperformed 1% niacinamide gel on photo and dermoscopy scoring. Fluorouracil caused more burning, itching and redness, so niacinamide is gentler but weaker there actinic keratosis RCT. If you have a lesion, a dermatologist should assess it.