Currently there are two main prescription medications that may be prescribed to help people quit smoking: Zyban and Chantix.

Zyban (Bupropion)

Bupropion is a prescription anti-depressant medication marketed under the brand names Wellbutrin (for depression) and Zyban (for smoking cessation).

Zyban does not contain nicotine and is thought to affect chemicals in the brain that are related to nicotine craving. Zyban can be used either alone or in conjunction with nicotine replacement therapy.

Zyban success rates

Zyban has been shown to be approximately twice as effective as placebo at three months, and approximately 1.5 times as effective as placebo at 1 year. Most studies show success rates of about 30% at 3 months and about 15% at 1 year.

Long-term success rates of Zyban are on the lower end, as smokers tend to relapse after longer periods of time. The success rate for Zyban is equivalent to the previously reviewed nicotine replacement therapy (NRT).

As with the other medication approaches to quitting smoking, Zyban is best used in conjunction with non-medication approaches.

Zyban is available in the generic form, bupropion.

Chantix (Varenicline)

Chantix was developed solely to help people quit smoking and is one of the newest medication approaches available. Chantix works by interfering with nicotine receptors in the brain. This interference decreases the pleasurable effects of the nicotine and reduces the unpleasant symptoms of nicotine withdrawal.


Chantix success rates

Chantix has been shown to be approximately three times as effective as placebo at both three months and 1 year. According to the manufacturer’s website,, studies have shown that at 3 months, 44% of those using Chantix were able to quit smoking.

The Effectiveness of Chantix and Zyban

Chantix has also been compared to Zyban and placebo. In the study, participants received Chantix, Zyban, or sugar pills (placebo) twice a day for three months. In addition to the pills, patients were also given a booklet on quitting smoking and received brief counseling at each visit.

The effectiveness showed that both Zyban and Chantix were more effective than sugar pills, and Chantix was more effective than Zyban:

  • Chantix - 44% quit
  • Zyban - 30% quit
  • Sugar pills - 17% quit

Preliminary studies suggest the one-year abstinent rate for Chantix is about 20%. Other studies have shown Chantix users were 60% more successful at quitting smoking at 1 year compared to Zyban.


As with other medication approaches, using Chantix along with psychological/behavioral interventions improves long-term results. Chantix is relatively new (released on the market in May 2006) and cannot be purchased as a generic.

For further information: Resources to Help Quit Smoking

Dr. William Deardorff is a clinical health psychologist and specializes in providing psychological services to patients with chronic pain and spinal conditions. He has led a private practice for more than 30 years.

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