Niacinamide is the least dramatic active on the shelf and probably the most useful. It doesn't sting, it doesn't require a tolerance-building programme, and it gets along with everything – which makes it the ingredient we suggest most often to people who've had a bad experience with something else.
What it is
Niacinamide is a form of vitamin B3 (also called nicotinamide). It's water-soluble, stable, and doesn't need the careful packaging that vitamin C demands — part of why it appears in so many formulations, from serums to moisturisers to cleansers.
Worth clearing up a common confusion: niacinamide in skincare and vitamin B3 as a supplement are the same vitamin doing entirely different jobs. Applying it topically is not a substitute for nutrition, and taking it as a supplement won't do what a serum does.
What it's used for
Niacinamide is chosen for the appearance of enlarged pores, uneven tone, and skin that looks shiny or dull. It's also widely used in formulas designed to leave the skin barrier feeling more comfortable and resilient — which is why it turns up so often in products aimed at sensitive skin.
It's a slow, cumulative ingredient rather than a dramatic one. Expect skin to look more even and refined over weeks, not overnight.
Percentage: why more isn't better
Most well-formulated products sit between 4% and 10%. Research and practical experience both suggest there's little to gain above that, and above roughly 10% some people experience flushing — a temporary warmth and redness that's harmless but uncomfortable.
If you've tried a very high-percentage niacinamide and found it irritating, that's worth knowing: the ingredient probably isn't the problem, the concentration is. A 5% formula may suit you perfectly.
How to use it
Morning, evening or both — niacinamide is genuinely flexible. Serums go on after cleansing and before moisturiser; if it's in your moisturiser, that's fine too.
It layers with essentially everything: retinol (where it helps make retinol more comfortable), the AHAs, salicylic acid, hyaluronic acid and ceramides.
You may have read that niacinamide and vitamin C shouldn't be combined. That claim comes from old research using raw ingredients under heat, not modern formulations — in practice they're used together routinely without issue. If your skin objects, use one in the morning and the other at night, but there's no need to avoid the pairing on principle.
Who it suits
Almost everyone, which is unusual for an active. It's particularly worth considering if your skin is reactive, if you're building a routine from scratch, or if you're using something demanding like retinol or an acid and want to keep skin comfortable alongside it.
Explore our niacinamide skincare, or see all active skincare.