Niacinamide

Niacinamide (vitamin B3) is the closest thing skincare has to a genuine do-everything ingredient — and also one of the most misunderstood, thanks to an outdated myth about mixing it with vitamin C. Here's what it actually does, and how to use it properly.

What it actually does

Niacinamide works on several fronts at once: it regulates oil production (helpful for both oily and dehydrated-but-oily skin), strengthens the skin barrier by boosting the skin's own ceramide and fatty acid production, fades post-acne marks and pigmentation by interrupting how pigment transfers to surface skin cells, and calms redness through a genuine anti-inflammatory effect. It's one of the few ingredients with legitimate evidence behind nearly every claim made about it.

What percentage should you use

2–5% is plenty for barrier support, redness, and general maintenance — this is the range to start with on sensitive skin. 5–10% is where most people land for oil control and fading post-acne marks; this is the concentration used in most clinical studies. Above 10% rarely adds benefit and raises the odds of temporary flushing, especially on reactive skin — more is not better here.

The vitamin C myth, debunked

You'll still see "never mix niacinamide and vitamin C" repeated online. This traces back to 1960s stability testing that used outdated formulations and irrelevant conditions (high heat, wrong pH) — it doesn't reflect modern products. Current dermatology consensus: the two are safe and effective together, and many well-formulated products already combine them. If you want to be cautious anyway, using vitamin C in the morning and niacinamide at night works fine too.

How to use it

Works morning or evening, under moisturiser, and layers safely with retinol, acids, and peptides — it's genuinely one of the least fussy actives to build a routine around. Daily use is fine; there's no need to cycle on and off like you would with retinol or strong acids.