|Short description Overview and Benefits   Champix (varenicline) is a medicine used to help with smoking cessation. The medication is available only to adults and with a prescription. It works best where smokers are committed to quit smoking and are receiving support. The smokers are required to set a date on which to stop smoking. The treatment typically takes 12 weeks. Champix (varenicline) works by reducing the pleasurable effects of smoking.   Smokers are usually addicted to nicotine (the chemical contained in tobacco). Nicotine binds the receptors and triggers the production of dopamine (a chemical messenger). This is what leads to the pleasurable effects. Varenicline binds these receptors thereby acting in two ways. First, it acts a partial agonist. It takes up the role of nicotine. This relieves the cravings. Second, the active ingredient acts as an antagonist where it works against nicotine to gradually reduce the pleasurable effects.