Acne gel

Gels spread thinly, dry quickly and leave almost no film, which is why they are the default format for oily and combination skin and for use under makeup or sunscreen. Common actives include salicylic acid, benzoyl peroxide, azelaic acid, niacinamide and retinoids.

The same properties that make gels comfortable on oily skin can make them harsh elsewhere. Alcohol-containing bases can sting on a compromised barrier, and a retinoid in gel form often feels stronger than the same active in a cream. Dry or sensitive skin may do better with a cream base, or with buffering — applying moisturiser before or after the treatment.

Use a thin layer on clean, dry skin, start with a few nights a week rather than daily, and always pair it with sunscreen, since several acne actives increase photosensitivity. Patch test new products, avoid stacking several strong actives at once, and see a dermatologist for deep, painful or scarring acne. Retinoid gels are not used in pregnancy.