Niacinamide Benefits: What It Does, Best Percentage and How to Use It

Niacinamide, a form of vitamin B3, has four well-studied benefits for skin: it fades dark spots, reduces oil, calms acne, and strengthens the skin barrier so skin holds water better. Most of the evidence comes from 2% to 5% products used once or twice a day for 4 to 12 weeks. It's one of the gentlest actives available and suits almost every skin type.

The sections below go through what the trials actually found for each benefit, which percentage to choose, whether daily use is safe, and how niacinamide fits alongside retinol, vitamin C and acids.

What does niacinamide do for your skin?

Niacinamide works on several things at once. A 2021 review in Antioxidants describes it as supporting cellular energy (NAD+ levels), reducing oxidative stress and inflammation, supporting the barrier and inhibiting pigmentation, and concludes that topical niacinamide reduces the progression of skin aging and hyperpigmentation in clinical trials. The same review is candid that there is no convincing evidence that it has specific molecular targets, which is a fair reminder that the mechanism is still being worked out.

Here is what the main studies tested:

Does niacinamide help with dark spots?

Yes, modestly and with steady use. In a study published in the British Journal of Dermatology, a 5% niacinamide moisturizer significantly decreased hyperpigmentation and increased skin lightness compared with the same moisturizer without niacinamide after four weeks. The researchers traced the effect to a step after pigment is made: niacinamide reduced the transfer of pigment packets (melanosomes) from pigment cells to surrounding skin cells by 35% to 68% in a lab model. It did not block tyrosinase, the enzyme many other brighteners target.

The larger 12-week trial of 5% niacinamide found reductions in hyperpigmented spots, red blotchiness and skin sallowness (yellowing) alongside fewer fine lines. Cleveland Clinic summarizes it this way: some research suggests skin care formulas with 5% niacinamide can help lighten dark spots.

Keep expectations realistic: niacinamide lightens spots gradually, over weeks. It works best as part of a plan that includes daily sunscreen, since UV keeps darkening spots. Our guide on how to fade dark spots covers the other ingredients worth combining with it.

Is niacinamide good for acne?

Yes, for mild to moderate inflammatory acne. A double-blind trial in the International Journal of Dermatology compared 4% nicotinamide gel with 1% clindamycin gel, a prescription antibiotic, in 76 people with moderate inflammatory acne. After eight weeks of twice-daily use, the two worked comparably: 82% of the nicotinamide group improved versus 68% on clindamycin, and the difference wasn't statistically significant. The authors pointed out that niacinamide avoids the antibiotic-resistance risk that comes with topical antibiotics.

Part of the benefit may come from oil control. DermNet notes that nicotinamide reduces sebum production as well as inflammation, and Cleveland Clinic says it may help regulate the amount of oil your glands produce, which may help prevent clogged pores.

For moderate to severe acne, cysts or scarring, niacinamide is a supporting player at best. See a dermatologist, who can combine it with retinoids, benzoyl peroxide or prescription treatment.

Does niacinamide reduce oil and shrink pores?

It reduces oil in some people; it doesn't physically shrink pores. In two trials of 2% niacinamide, the Japanese group (100 people, 4 weeks) had a significantly lower sebum excretion rate than placebo, while the white group (30 people, 6 weeks, split-face) showed lower casual sebum levels but no significant change in the excretion rate. So results vary from person to person.

On pores, Cleveland Clinic is direct: nothing has been proven to reduce the actual size of your pores, though niacinamide may help minimize their appearance by keeping skin smooth and clear. Less oil sitting in pores tends to make them look smaller. More on that in how to minimize pores, and if shine is your main concern, an oily skin routine built around a gentle cleanser, light moisturizer and sunscreen is the place to add it.

Does niacinamide help the skin barrier?

Yes, and this is one of its best-documented effects. In the British Journal of Dermatology, researchers found nicotinamide increased ceramide production about four- to five-fold in cultured skin cells, and on people with dry skin, topical nicotinamide raised ceramide and free fatty acid levels in the outer skin layer and decreased transepidermal water loss. Ceramides are the lipids that seal gaps between skin cells, so more of them means less water escaping.

DermNet reports the same barrier effect and notes that nicotinamide moisturizers improved barrier function in rosacea patients. That makes niacinamide a reasonable pick if your skin is reactive; introduce it slowly, as described below.

What percentage of niacinamide should you use?

2% to 5% is the range with the most evidence, and higher isn't proven to be better. Each of the benefits above was shown at 2%, 4% or 5%. Cleveland Clinic notes that most skin care products contain 5% or less niacinamide and suggests starting with a low concentration if your skin is sensitive.

• 2%: the strength used in the sebum trials; a good start for sensitive skin.
• 4%: the strength in the acne trial.
• 5%: the strength in the aging and dark spot trials, and a sensible target for most people.
• 10% and above: widely sold, but we found no head-to-head trial showing 10% beats 5%, and stronger serums are more likely to sting sensitive skin.

If a 10% serum leaves you red or itchy, a 5% product is very unlikely to be a step down in results.

Can you use niacinamide every day?

Yes. The major trials used it twice a day for 8 to 12 weeks, and Cleveland Clinic says it can be used once or twice daily after gentle cleansing. The 2021 review describes topical niacinamide as well tolerated by the skin.

Side effects are uncommon. Cleveland Clinic lists rare allergic reactions, itching, mild burning and redness, and suggests a patch test on your forearm for 24 hours before using a new product on your face. Niacinamide is also different from niacin (nicotinic acid): DermNet notes that nicotinamide does not cause flushing, unlike its precursor nicotinic acid.

Give it time. Dark spot changes appeared at four weeks in one trial, while wrinkle and texture changes were measured over 12 weeks.

Can you use niacinamide with retinol, vitamin C or acids?

Yes. Niacinamide is one of the easiest actives to pair. Cleveland Clinic lists vitamin C, retinol, ceramide moisturizers, glycolic acid and hyaluronic acid among good partners, and notes niacinamide may soothe irritation from strong ingredients like retinol or glycolic acid. DermNet adds that people often use it when they can't tolerate retinoids or fruit acids.

The warning about niacinamide and vitamin C cancelling each other out circulates widely, but none of the clinical sources we reviewed supports it, and Cleveland Clinic recommends the pairing. We go through this and other combinations in skincare ingredients not to mix. If you're adding niacinamide to a retinoid routine, our retinol for beginners guide covers the order and schedule. Cleveland Clinic's one caution is to avoid using too many skin care products at once.

A simple order: cleanse, moisturize, then apply niacinamide. Cleveland Clinic suggests using it after gentle cleansing, and after your moisturizer for best results. In the morning, finish with sunscreen.

Who should use niacinamide?

Almost anyone, which is a large part of its appeal. Cleveland Clinic notes it may calm redness linked to acne, rosacea and eczema, and DermNet describes it as well tolerated. It's a natural first active for oily, acne-prone or combination skin because of its effect on oil, and a reasonable one for dry skin because of its effect on ceramides. If your skin is very reactive, start with a 2% to 5% product a few times a week, then move to daily use once you know it agrees with you.

How do you know if a product has enough niacinamide?

Check the ingredient list and the stated percentage. Our guide to reading ingredient labels explains how to judge where niacinamide sits in the list and what that says about the amount. The label may also list it as nicotinamide.

This is where Pori can save time. Its ingredient scanner (part of Pro) reads a product's barcode or label and flags each ingredient as beneficial, use with caution or avoid for your skin type, using fixed rules over a curated ingredient list, so you can see whether that new serum is built around niacinamide or just mentions it. A free selfie scan also tracks Pigmentation & Tone and Pores & Texture over time, which helps you judge a 12-week trial honestly. The app looks at appearance only: it isn't a medical device and can't diagnose acne, melasma or rosacea, so see a dermatologist for those.