How to Use Adapalene Dr. King recommends applying a thin layer of the gel (about a pea-sized amount) onto clean, dry skin. Because adapalene works to both treat and prevent acne, it should be applied across the entire face, not as a spot treatment. As far as timing is concerned, adapalene, just like any other retinol, should be applied in the ... Adapalene topical is a medicine similar to vitamin A that helps the skin renew itself and treat severe acne. Learn how to use it, what side effects to watch out for, and what precautions to take before using it. Adapalene is used in the treatment of Acne. View Adapalene’s uses , side-effects, drug interactions, expert advice and user FAQs only on 1mg.com. Description Adapalene is used to treat acne. It works partly by keeping skin pores clear. Adapalene is available only with your doctor's prescription.