A medication or medicine is a drug taken to cure or ameliorate any symptoms of an illness or medical condition. The use may also be as preventive medicine that has future benefits but does not treat any existing or pre-existing diseases or symptoms.Dispensing of medication is often regulated by governments into three categories—over-the-counter (OTC) medications, which are available in pharmacies and supermarkets without special restrictions; behind-the-counter (BTC), which are dispensed by a pharmacist without needing a doctor's prescription, and prescription only medicines (POM), which must be prescribed by a licensed medical professional, usually a physician.