Varenicline tartrate is primarily used as a smoking cessation aid. It works by targeting nicotine receptors in the brain, reducing both the pleasurable effects of smoking and the symptoms of withdrawal. This dual action helps individuals quit smoking by decreasing cravings and making smoking less satisfying. It is often prescribed as part of a comprehensive program that includes behavioral support and counseling to enhance its effectiveness. The treatment typically starts one week before the planned quit date and continues for 12 to 24 weeks, depending on the individual's progress. It is considered effective for long-term smoking cessation when used as directed.