On the Label: Niacinamide

Niacinamide. A form of vitamin B3, sometimes listed as nicotinamide. You’ll find it in serums, moisturisers and even sunscreens. Studies mostly point to two things: shine looks calmer, and redness looks a bit softer after a few weeks^[1][2]. It’s designed to support your skin, not treat it. This entry pulls together published studies and a safety review, numbered at the end.

Does it calm an oily, shiny face?

In a double-blind study, 100 Japanese adults used a moisturiser with 2% niacinamide or a placebo moisturiser on the face for 4 weeks, 50 in each group^[1]. The niacinamide group produced clearly less oil at both 2 and 4 weeks.

A second group, 30 white participants using it on half the face for 6 weeks, was less clear-cut. The oil sitting on the skin’s surface dropped, but the rate the skin made oil did not change in a meaningful way.

Heat is when shine is hardest to manage, so this is the result that matters most here. None of these studies set out to test it in heat, though. They show less oil, not a face that stays matte through a heatwave.

What about redness, dark spots and fine lines?

In one study, 50 white women with sun-aged skin applied 5% niacinamide to half the face and a plain base cream to the other half, twice a day for 12 weeks. Neither they nor the researchers knew which side was which^[2]. The niacinamide side showed fewer fine lines, fewer dark spots, less red blotchiness and less yellowish dullness, and the skin was more elastic.

In another, 18 Japanese women with dark patches used a 5% cream against a plain base, and 120 people with tanned faces were split between a plain base, sunscreen, and 2% niacinamide with sunscreen^[3]. After 4 weeks, niacinamide clearly faded dark patches and brightened skin compared with the base cream alone.

Both papers come from researchers employed by Procter & Gamble, a company that sells skincare, and the groups are small. That doesn’t make the results wrong, but it’s worth knowing.

Can it help skin that feels tight and dry?

Ceramides are fats that hold the outer layer of skin together and keep water in. One study found that applying niacinamide raised ceramides and other fats in that outer layer and cut water loss through dry skin^[4]. That fits the tight feeling after a day in air conditioning, but the study looked at dry skin in general, not air-conditioned rooms.

What strength should you look for, and will it sting?

The studies above used 2% and 5%. A safety review by the CIR, an expert panel that assesses cosmetic ingredients, found no stinging in clinical tests at strengths up to 10%^[5]. Use tests found no irritation up to 5%, and a 21-day test of repeated application up to 5% caused none either. It didn’t trigger allergies or make skin react to light.

So stinging isn’t typical. Above 10%, these sources have no data, so a bigger number on the bottle isn’t proof of a better result. If you’re new to it, a strength close to what was studied is a sensible start. Add one new product at a time, and if your skin reacts, stop and see a dermatologist.