Tretinoin, also referred to as all-trans retinoic acid (ATRA), is a medication derived from vitamin A that is most recognized for its roles in dermatology and oncology. It is widely used topically for treating acne, improving photoaged skin, and managing pigmentation disorders such as melasma. Oral tretinoin, meanwhile, has a distinct role in cancer therapy, specifically as an established treatment for acute promyelocytic leukemia (APL) by promoting normal development of certain blood cells. Besides its main indications, tretinoin is sometimes used off-label for conditions like early stretch marks or various disorders of skin cornification, demonstrating its versatility as a dermatological and systemic agent.