Niacinamide: What It Actually Does for Skin

Niacinamide — vitamin B3, sometimes written nicotinamide on an INCI list — has become the active everyone recommends. For once the enthusiasm rests on something: it's one of the best-studied molecules in cosmetic dermatology, and one of the few that works on several fronts without irritating.

What it does

It limits pigment transfer

Unlike an acid, it doesn't exfoliate. It intervenes earlier: it slows the transport of melanin towards surface cells. That's what makes it useful on uneven tone and on marks left by blemishes — the subject we cover in our piece on dark spots.

It strengthens the skin barrier

It supports ceramide production — the lipids that hold cells together. A stronger barrier means less water evaporating, less redness, and skin that tolerates the rest of your routine better. This is often the effect people notice fastest.

It works on the look of oil and pores

On oily skin it reduces the greasy appearance and makes pores less visible. Be precise about the wording: it doesn't shrink a pore — nothing does — but an unclogged pore is far less noticeable. See our piece on oily skin.

Which concentration

Most of the data covers concentrations of 2 to 5%. Above 10%, there's no clear extra benefit, but the risk of redness and stinging rises for sensitive skin. The 20% formulas you see around are marketing, not science.

What to combine it with

• Hyaluronic acid: yes, without reservation. Different mechanisms, they layer beautifully — see the Hyaluronic Acid Serum.
• Glycolic acid: yes, but separately. Niacinamide in the morning, acid at night. Stacking them back to back adds nothing and irritates.
• Retinol: yes, and it's a good idea — niacinamide softens retinol's irritation.
• Sunscreen: essential if you're after even tone. Without it, the work undoes itself daily.

The vitamin C myth

You'll often read that niacinamide and vitamin C must never be combined. That idea comes from 1960s studies run at high temperature on pure forms of both molecules — conditions with nothing in common with a serum on a face. In modern cosmetic formulations, the pairing is not a problem. At worst, a mild passing tingle on some skin.

How long it takes

Comfort and reduced redness are often noticeable in two to four weeks. Even tone takes eight to twelve. As always: a photo at the start, same light, same time of day — it's the only reliable measure.

Frequently asked

Morning or night?

Either works. Morning is practical because it leaves the evening free for acids or retinol.

It stings — is that normal?

A mild tingle at first can happen, especially above 10%. Persistent redness or a burning sensation are not normal: space out applications, or move to a lower concentration.

Is it suitable for sensitive skin?

That's one of its great advantages: yes, generally better than most brightening actives. Start every other day.

The full INCI list for every formula is published on its product page.