Differin is best known for its adapalene gel, a tretinoin-like retinoid lauded in the Reddit skincare community for being an effective, prescription-strength acne treatment available over the counter. Users consistently praise its cost-effectiveness and straightforward formulation that targets acne without a ton of fillers or irritants. However, many also report a tough adjustment period with dryness and irritation, making it a product mostly favored by those with some retinoid experience or willing to commit to skin acclimation.