A Ret Gel contains tretinoin, a form of vitamin A as its active ingredient. It is used for the topical treatment of acne. During the treatment with A Ret Gel, it is recommended to avoid being exposed to sunlight for too long after applying this medicine. You should use sunscreens with at least SPF 30 before going outdoors. Drink plenty of water and fluids to keep yourself hydrated, as it can make your skin dry. Do not pop your acne as it may lead to bacteria and pus spreading on the skin which can lead to the spread of acne and acne scars.