How can bupropion (Zyban) help me quit smoking?

Dr. Darria Long Gillespie, MD
Emergency Medicine
Bupropion (Zyban) is used to treat depression. It is also the antidepressant drug most commonly used to quit smoking. It may improve mood or block the effects of nicotine, relieving withdrawal symptoms. If you use bupropion to quit, you will likely start by taking it once a day for 3 days, then twice a day for 7 to 12 weeks. At the end of the first week, you stop smoking. Bupropion can also be used with a nicotine patch to raise your chances of success.

This answer was adapted from Sharecare's award-winning AskMD app. Start a consultation now to find out what's causing your symptoms, learn how to manage a condition, or find a doctor. 
Frank T. Leone, MD
Pulmonary Disease

Bupropion helps reduce the cravings that you may experience when you quit smoking. You will be required to start the treatment 7 to 10 days before your quit date. The advantage of bupropion is that it is often combined with nicotine replacement therapy.

Howard J. Shaffer, PhD
Addiction Medicine
Bupropion, an antidepressant, also works as a stop-smoking aid. It was first introduced under the brand name Wellbutrin. Smokers who used Wellbutrin often reported a lessening in the desire to smoke. After the drug was tested among smokers, the Food and Drug Administration (FDA) approved it for this use under the brand name Zyban. Unlike nicotine patches or gum, Zyban doesn't put nicotine into the body. Instead, it eases nicotine withdrawal symptoms, especially irritability, frustration, anxiety, difficulty concentrating, and depression.
Quitting smoking is one of the most important things you can do to lower your risk factors for serious cardiovascular disease. While many medications for quitting smoking contain nicotine, not all do.
One prescription medication for smoking cessation that does not contain nicotine is bupropion (Zyban, Wellbutrin SR).
What It Does: Bupropion is an anti-depressant that is believed to work by increasing certain brain chemicals.
How to Take It: Start taking the medication 1 week prior to your quit date to reach adequate blood levels. Then take 150 mg/day for 3 days, and then 150 mg/day twice a day (or once a day if a higher dose is not tolerated). Follow up with your doctor within 1 to 2 weeks of starting. 
How Long to Use It: Continue using the medication for at least 7 to 12 weeks. It can be used for up to 6 months to prevent relapse.
Precautions/Contraindications: Taking bupropion may cause insomnia, agitation, dry mouth, headache, seizures, mood changes and/or suicidal thoughts. Notify your doctor and stop taking bupropion if you have changes in behavior or mood, or suicidal thoughts. Bupropion is not for use in people with seizure or eating disorders, or those taking MAO inhibitors for depression. 
Other Considerations: Note that if bupropion is needed for 6 months, it is recommended that you be evaluated for an underlying condition of depression, which may be better managed on a different medication.
Bupropion (Zyban) is a prescription anti-depressant in an extended-release form that reduces symptoms of nicotine withdrawal. It does not contain nicotine. This drug acts on chemicals in the brain that are related to nicotine craving. It can be used alone or together with nicotine replacement therapy (NRT). Bupropion works best if it is started 1 or 2 weeks before you quit smoking. The usual dosage is one or two 150 mg tablets per day.
This drug should not be taken if you have ever had seizures, heavy alcohol use, serious head injury, bipolar (manic-depressive) illness, or anorexia or bulimia (eating disorders).
Some doctors may recommend combination therapy for heavily-addicted smokers, such as using bupropion along with a nicotine patch and/or a short-acting form of NRT (such as gum or lozenges). The combination has been found to work better in some people than using any one part alone.