Bupropion is a medication primarily used as an antidepressant and smoking cessation aid. It is marketed as Wellbutrin and Zyban among other trade names. It is one of the most frequently prescribed antidepressants in the United States and Canada, although in many English-speaking countries, including the United Kingdom, Australia and New Zealand, this is an off-label use. Bupropion is taken in tablet form and is available only by prescription in most countries. Chemically, bupropion is in the aminoketone family.