What is niacinamide? Benefits, how to use it and side effects

Key takeaways

• Niacinamide is a form of vitamin B3. Unlike niacin, it doesn’t cause flushing.

• Studies link it to less oil, a stronger-feeling skin barrier, fewer dark spots and smoother-looking skin, mostly at 2% to 5%.

• Most products contain 5% or less. Some serums go up to 10% or 20%, but the studies we found tested 5% or lower, so there’s no evidence higher strengths work better.

• It’s generally gentle. Side effects like itching, mild burning or redness are rare.

• You can use it with vitamin C and retinol. Give it about a month for oil and dark spots, and about three months for fine lines.

What is niacinamide?

Niacinamide, also called nicotinamide, is a form of vitamin B3. DermNet describes it as “the water-soluble, active form of vitamin B3,” found in foods like yeast, lean meats, fish, nuts and legumes.

It’s easy to confuse with niacin (nicotinic acid), the other main form of B3. The difference matters: niacin can cause flushing, and niacinamide doesn’t. A 2021 review notes that “unlike nicotinic acid, nicotinamide does not reduce cholesterol or cause flushing,” which is part of why it’s so widely used on skin.

What does niacinamide do for your skin?

Niacinamide has been tested in a number of human studies, although many are small and several were run by skincare companies. Here’s what they found:

• Oil. In a 2006 study, a moisturizer with 2% niacinamide lowered the rate of oil production over two to four weeks in a trial of 100 Japanese participants, half of whom used a placebo. In 30 white participants, it reduced surface oil but not the production rate.

• Skin barrier. In lab studies, niacinamide increased the skin’s production of ceramides, the fats that help hold water in. Applied to dry skin, it raised ceramide levels in the outer layer and reduced water loss.

• Dark spots. A 2002 study found that 5% niacinamide reduced hyperpigmentation after four weeks. It appears to work by blocking the transfer of pigment to skin cells rather than by stopping pigment production. In a small 2011 trial of 27 people with melasma, each person used 4% niacinamide on one side of the face and 4% hydroquinone on the other for eight weeks. Both sides improved, with good to excellent results in 44% of patients on the niacinamide side and 55% on the hydroquinone side, and niacinamide caused fewer side effects.

• Fine lines, redness and sallowness. In two 12-week studies, each with 50 women, 5% niacinamide improved the look of fine lines, dark spots, red blotchiness, yellowing and texture compared with a plain moisturizer.

• Acne. In a 1995 trial of 76 people with moderate inflammatory acne, a 4% niacinamide gel was comparable to a 1% clindamycin antibiotic gel after eight weeks: 82% improved on niacinamide and 68% on clindamycin, a difference that wasn’t statistically significant.

It won’t shrink pores, but less oil and smoother skin can make them look smaller. Our guide to minimizing the look of pores explains why. DermNet also notes that niacinamide isn’t a sunscreen and doesn’t prevent sunburn.

What about niacinamide supplements?

Oral nicotinamide is a separate, medical use. In a 2015 trial of 386 people who’d had at least two nonmelanoma skin cancers, taking 500 mg twice a day for a year lowered the rate of new ones by 23% compared with placebo, and the benefit disappeared after people stopped. That’s a treatment for people at high risk, discussed with a doctor, not a reason to take supplements for general skin health.

What strength should you use?

Studies mostly used 2% to 5%. The 2021 review notes that cosmetics are mainly formulated at 4% to 5%, and that niacinamide is well tolerated at the concentrations normally used, which it puts below 5%. A safety review of the ingredient found no stinging at up to 10% and no irritation in use tests at up to 5%.

Many serums now sell 10% or even 20%. The studies we found all tested 5% or less, and none showed that 10% or 20% works better, so higher isn’t proven to be better. Cleveland Clinic suggests starting with a low concentration if your skin is sensitive. Our list of the best niacinamide serums compares strengths and formulas.

Side effects

Niacinamide is generally considered gentle. Cleveland Clinic says it can rarely cause an allergic reaction, itching, a mild burning sensation or redness, and suggests a patch test: apply a little to your forearm and wait 24 hours.

DermNet adds that niacinamide can often be used by people who can’t tolerate retinoids or fruit acids, and that if a twice-daily niacinamide gel feels too drying, you can cut back to once a day or every other day.

Can you use niacinamide with vitamin C?

Yes. The worry comes from older research that combined pure niacinamide and ascorbic acid at high temperatures, which can form nicotinic acid, the flushing form of B3. That doesn’t reflect how people use skincare at room temperature, and Cleveland Clinic lists vitamin C among the ingredients niacinamide pairs well with. Some formulas already combine the two.

How to use niacinamide

• Use it once or twice a day. Cleveland Clinic says it can be used once or twice daily after gentle cleansing.

• Apply it before heavier products. As a serum, it usually goes after cleansing and before moisturizer and sunscreen. Our guide to skincare routine order shows where it fits.

• Pair it with other ingredients. Cleveland Clinic lists hyaluronic acid, ceramide moisturizers, vitamin C, glycolic acid and retinol as good partners.

• Don’t count on it to prevent retinol irritation. In a small 2024 study, 3% niacinamide didn’t reduce discomfort from retinol, so ease into retinol slowly either way.

• Wear sunscreen. Niacinamide can help with dark spots, but it doesn’t protect against the sun that causes them.

How long does niacinamide take to work?

It depends on what you’re treating. In studies, changes in oil showed up within two to six weeks, dark spots improved after about four weeks, and acne was measured at eight weeks. The fine-line and texture studies ran for 12 weeks. A good rule of thumb is about a month for oil and tone, and about three months for lines and texture.

Frequently asked questions

What does niacinamide do to your face?

It can help reduce oil, support the skin barrier, fade dark spots and improve the look of fine lines, redness and uneven texture. Most of the evidence comes from studies using 2% to 5%.

Is it okay to use niacinamide every day?

Yes, for most people. Cleveland Clinic says it can be used once or twice a day, and it’s well tolerated at the strengths normally used. If it feels drying, use it less often.

What should you not mix with niacinamide?

There’s no common ingredient you need to avoid. The old warning about vitamin C comes from high-temperature lab conditions, not normal use. As with any new product, add one at a time so you can tell what’s causing a reaction.

Is niacinamide the same as niacin?

No. Both are forms of vitamin B3, but niacin can cause flushing and niacinamide doesn’t.

Can niacinamide cause breakouts?

Breakouts aren’t on Cleveland Clinic’s list of niacinamide’s rare side effects, and niacinamide has been studied as an acne treatment. If you break out after starting a new serum, another ingredient in the formula may be the cause, so check the full ingredient list.