Varenicline is a drug used in conjunction with counseling and education from a physician or psychiatrist to help adults 18 and over quit smoking. The drug is usually used by individuals who desire to stop smoking, or need help in quitting smoking due to chronic dependence, addiction, or past failed attempts. Users of varenicline may smoke during the first week of their treatment, but are encouraged to stop smoking on a specific quit date, which can be determined by the smoker or smoker's physician. The drug works by stopping the pleasant effects of nicotine, from smoking, on the brain. Varenicline requires a prescription and may be prescribed for other uses. Be sure to ask your doctor or pharmacist for more information.