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Niacinamide

Niacinamide (vitamin B3): good trial evidence for visible dark spots; limited evidence for breakouts, skin barrier, oil and pores.

What it is

Niacinamide, also called nicotinamide, is the amide form of vitamin B3. It is used in leave-on skincare, and the trials cited below tested it at 2% to 5%. Korea's Ministry of Food and Drug Safety (MFDS) lists niacinamide at 2–5% among its notified whitening ingredients.

Evidence grades by concern

ConcernGradeCitations
Post-inflammatory hyperpigmentationAKimball 2010
MelasmaALee 2014, Korea MFDS 2025
Solar lentigines / frecklesABissett 2004, Korea MFDS 2025
Comedonal acneCAlthwanay 2024
Inflammatory acneCShalita 1995
Chronic barrier impairmentCDraelos 2005
Persistent erythemaCDraelos 2005, Bissett 2004
Excess sebumCDraelos 2006
Enlarged pores / blackheadsCno direct citation

Grade A: strong guideline recommendations or Korean MFDS notified actives. B: randomized controlled trials or systematic reviews. C: mechanism, small or uncontrolled studies.

What the evidence shows

The A grades for pigmentation reflect Korea's MFDS notification of niacinamide (2–5%) as a whitening ingredient; the trials below are supporting evidence.

Post-inflammatory hyperpigmentationA

In a 10-week double-blind trial of 202 women aged 40 to 60, moisturizers with 4% niacinamide plus 2% N-acetyl glucosamine reduced the appearance of facial hyperpigmentation more than the vehicle did (Kimball 2010). The product combined two ingredients, and the trial measured facial pigmentation in general, not marks left by pimples specifically.

MelasmaA

In an 8-week double-blind trial of 42 Korean women, a cream with 2% niacinamide plus 2% tranexamic acid reduced the appearance of irregular facial pigmentation compared with vehicle, with sunscreen used by both groups (Lee 2014). It was a combination product, and the trial reported facial pigmentation rather than melasma specifically.

Solar lentigines / frecklesA

In a 12-week double-blind, split-face study of 50 women aged 40 to 60, a moisturizer with 5% niacinamide improved hyperpigmented spots, fine lines, texture and red blotchiness compared with the same moisturizer without it (Bissett 2004).

Comedonal acneC

The evidence is limited. A systematic review of topical acne treatments cites a 41-person randomized trial in which niacinamide reduced sebum production (Althwanay 2024). Our evidence file contains no trial that counted blackheads or whiteheads directly.

Inflammatory acneC

In a double-blind trial that enrolled 76 people with moderate inflammatory acne (49 were included in the efficacy results), 4% nicotinamide gel and 1% clindamycin gel gave comparable results after 8 weeks, with no significant difference between them (P = 0.19; Shalita 1995). The paper gives the share who improved on nicotinamide as 82% in one place and 86% in another, against 68% for clindamycin. There was no placebo group, so the trial shows that niacinamide performed similarly to an antibiotic gel, not that it works better than no treatment. The study was supported in part by the company behind the gel, and we found no independent repeat, so we grade this as C.

Chronic barrier impairmentC

In a 4-week study of 50 women with rosacea, a commercial moisturizer with 2% niacinamide improved barrier measurements on a treated forearm compared with an untreated forearm (Draelos 2005). No version of the moisturizer without niacinamide was tested, so the study cannot separate the effect of niacinamide from that of the moisturizer itself. Face results had no comparison group. The manufacturer funded the study and two authors were its employees, as the paper discloses. We grade this as C.

Persistent erythemaC

The rosacea study above reported less facial redness, but with no comparison group on the face (Draelos 2005), and the 12-week study of aging facial skin reported less red blotchiness (Bissett 2004). Both studies are small and short (4 and 12 weeks), and the rosacea study cannot separate niacinamide from its moisturizer base.

Excess sebumC

In a trial of 100 Japanese women chosen because they saw their skin as oily, a gel with 2% niacinamide and 1% d-panthenol lowered sebum excretion rate after 2 and 4 weeks compared with the same gel without either ingredient. Because the test gel also contained panthenol, the result cannot be credited to niacinamide alone. In a separate 30-person split-face study in the US, sebum excretion rate did not change and casual sebum level just missed significance at 6 weeks (P = 0.055; Draelos 2006). Two authors worked for the manufacturer. We grade this as C.

Enlarged pores / blackheadsC

The evidence is limited. The sebum studies above measured oil production, and the paper does not report pore size. We have not found a trial in our evidence file that directly measured pores.

What it does not do

Niacinamide on its own has not been shown to treat melasma: the pigmentation trials tested it combined with N-acetyl glucosamine or tranexamic acid, and in two of them both groups also used sunscreen, so the benefit was on top of sun protection, not instead of it. Our evidence file has no trial showing that niacinamide removes acne scars or shrinks pores.

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