Niacinamide

In plain English: Shiny by lunchtime, or stuck with dark marks from old pimples? This is the one ingredient that helps with both, and it almost never irritates. If you’re only going to try one serum, start here.

Niacinamide is a form of vitamin B3, and it is the closest thing skincare has to a universal team player. It works at a skin-friendly pH, plays well with nearly every other active, and rarely irritates.

What it does

• Regulates oil. Studies on 2% niacinamide have shown reduced sebum production after four weeks, which is why it is a favourite for oily Indian skin.
• Strengthens the barrier. It boosts the skin’s own production of ceramides, reducing water loss.
• Fades marks. It slows the transfer of pigment to skin cells, helping with post-acne marks and uneven tone.
• Calms redness. It has anti-inflammatory effects useful for acne and sensitivity.

How to use it

Apply two or three drops after cleansing and before moisturiser, morning, night or both. It suits every season and every skin type, though very sensitive skin should start at 2 to 5%.

Who should skip it

Almost no one. If a niacinamide product stings, the culprit is often another ingredient in the formula, such as fragrance or a high level of zinc. Try a simpler formula before giving up on the ingredient.