Niacinamide is a form of vitamin B3. Taken by mouth it prevents and treats deficiency; applied to skin it is one of the better-evidenced skincare ingredients, used for acne, redness, pigmentation and barrier repair. It is also used at high doses to reduce skin cancer recurrence.

What is Niacinamide?

Niacinamide — also called nicotinamide — is one of two forms of vitamin B3. The other is nicotinic acid (niacin), and the difference between them is practically important:

FormAlso calledKey difference
NiacinamideNicotinamideNo flushing; no cholesterol effect
Nicotinic acidNiacinCauses flushing; used at high dose for cholesterol

Nicotinic acid causes flushing — intense heat and redness of the face and upper body — at higher doses. Niacinamide does not, which is why it is the form used in supplements and skincare where flushing would be unwelcome.

The reverse is also true: niacinamide does not lower cholesterol. If you were prescribed niacin for lipids, niacinamide is not a substitute.

In the body, vitamin B3 becomes NAD and NADP — coenzymes involved in a very large number of reactions, including energy production and DNA repair. Deficiency causes pellagra, with dermatitis, diarrhoea and dementia.

It is a food supplement and cosmetic ingredient rather than a registered medicine, so it does not appear in the medicine price register as a standalone product. It appears there as a component of multivitamins.

What is Niacinamide commonly used for?

In skincare — where most current interest is:

Typical concentration is 4–5% in cosmetic products, which is what most studies used. Higher concentrations — 10% and above — are marketed as stronger and are more likely to irritate without clearly working better.

By mouth:

Who commonly looks for Niacinamide and why

What to check on the label before taking Niacinamide

For skincare:

For supplements:

Safety, interactions and when to seek professional advice

Niacinamide is well tolerated. At supplement doses side effects are uncommon; higher doses can cause nausea, stomach upset and headache.

High oral doses — 3 g daily and above — have been associated with liver toxicity, which is why the skin cancer studies used 500 mg twice daily and not more.

On skin, the usual problems are mild stinging, redness or irritation, more likely at higher concentrations or on already-compromised skin.

Speak to a doctor or pharmacist before taking oral niacinamide beyond multivitamin amounts if you:

Stop and seek advice for persistent nausea or abdominal pain, yellowing of the skin or eyes, dark urine, or unusual tiredness.

For skincare, stop if the product stings, burns or worsens redness, and reduce frequency rather than pushing through.

See a doctor rather than self-treating if:

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Frequently asked questions

What is niacinamide used for? In skincare, for acne, redness, pigmentation and barrier repair. Taken by mouth, for vitamin B3 deficiency and — at specific doses — to reduce recurrence of non-melanoma skin cancer.

Is it the same as niacin? No. Both are vitamin B3, but nicotinic acid (niacin) causes flushing and lowers cholesterol; niacinamide does neither. They are not interchangeable.

What concentration should I use on skin? 4–5% is the well-studied range. Higher concentrations are more likely to irritate without working better.

Does it help acne? Yes, reasonably — it reduces inflammatory lesions and is gentler than benzoyl peroxide or retinoids. Moderate or severe acne still needs proper treatment.

Can I use it with vitamin C? Generally yes. The old advice against combining them has largely been overstated, though some people find the combination irritating.

Does it prevent skin cancer? A trial found 500 mg twice daily reduced new basal cell and squamous cell cancers by around 23% in people who had already had several. Discuss it with a doctor rather than self-starting.

Is it safe at high doses? Doses of 3 g daily and above have been linked to liver toxicity. The studied preventive dose is 500 mg twice daily.

Do I need a supplement? Most people get enough from diet and any multivitamin. Deficiency is uncommon outside malnutrition or alcohol dependence.