Adapalene

Adapalene is a third-generation synthetic retinoid, available over the counter at 0.1% (e.g. Differin) and by prescription at 0.3%. It selectively binds RAR-β/γ receptors, normalising follicular keratinisation and preventing microcomedones — the precursors of all acne lesions. It also has inherent anti-inflammatory activity, outperforming tretinoin on inflamed papules in head-to-head trials. Adapalene is more photostable than older retinoids and its peeling profile, while real, is more predictable. Use a pea-sized amount on dry skin at night, moisturise, and wear SPF daily. Pregnancy contraindicates use. It is the first-line topical retinoid for mild to moderate acne worldwide.