Differin Gel (Adapalene 0.1%)

Unlike tretinoin, adapalene causes 40% less irritation and redness, making it tolerable for adults and teens alike. Dermatologists call it the most important OTC launch of the decade, delivering prescription-strength adapalene at $15 per tube — 80% cheaper than prior clinic visits and copays, with clinical trials showing 70% clearance of inflammatory acne at 12 weeks.