Used primarily as a medication to help individuals quit smoking by reducing cravings and withdrawal symptoms. It works by partially activating nicotine receptors in the brain, which decreases the pleasurable effects of smoking and eases the transition to cessation. Often prescribed as part of a comprehensive smoking cessation program, including counseling and behavioral support. It is taken orally in tablet form, typically starting one week before the planned quit date to build up effectiveness. Common side effects include nausea, headaches, and vivid dreams, but it is generally well-tolerated. Not recommended for use during pregnancy or in individuals with severe kidney problems.