Does Niacinamide Actually Shrink Pores? Here's What the Studies Say

Niacinamide (vitamin B3) is one of the rare skincare ingredients where the internet hype and the clinical evidence actually line up. It won't magically close pores forever — nothing does — but it targets the two things that make pores look bigger: excess oil and loss of firmness around the pore opening.

The headline study: in a controlled trial, 2% topical niacinamide significantly reduced sebum (oil) output over four weeks. Separate research found that niacinamide also fades the look of dark spots by slowing pigment transfer to skin cells — which is why it shows up in so many 'brightening' products.

How to use it: a niacinamide serum like The Ordinary's 10% goes on after cleansing and before moisturizer, morning or night. It's one of the most tolerable actives out there, so it layers fine with almost everything (including retinol and vitamin C, despite old internet myths).

If oil is your main concern, pair it with a gentle foaming cleanser and, for active breakouts, a benzoyl peroxide wash a few times a week. Consistency beats concentration — daily 10% will do more than an occasional stronger product.