Varenicline (Chantix) Make an Appointment Ask a Question Search Conditions Varencline is a relatively new and different type of medication for smoking cessation. Chantix is a prescription medicine that works by blocking some of nicotine's effects in the brain. Read the information below and talk to your doctor about Varencline to see if it is appropriate for you. Chantix is an effective non-nicotine prescription medication for many tobacco users trying to quit. Before your Quit Date, talk to your doctor about Chantix and if it is appropriate for you. Your doctor will advise you about how to take this medicine. Chantix should be started one week before your Quit Date and can be taken while continuing to smoke until the Quit Date. In general, Chantix is taken once a day for three days and then increased to twice a day. Chantix is generally taken for at least 12 weeks. If you have quit smoking at the end of 12 weeks, your doctor may advise taking for 12 more weeks. The most common side effects are nausea, vomiting and trouble sleeping. Take Chantix after eating with a full glass of water. These side effects usually become less with continued use. When taken every day, Chantix reduces the rewarding effects of smoking. Once you quit smoking, it helps to lessen cravings and withdrawal symptoms. Effectiveness Chantix is an effective medicine to help people quit smoking. About 40% of people who use Chantix to quit, stay quit after 6 months. References Fiore MC, Jaén CR, Baker TB, et al. Treating Tobacco Use and Dependence: 2008 Update. Clinical Practice Guideline. Rockville, MD: U.S. Department of Health and Human Services. Public Health Service. May 2008. This information has been approved by Thomas Ylioja, MSW, PhD (December 2018).