Zyban is the brand name for bupropion, a prescription drug that reduces the symptoms of nicotine withdrawal. Bupropion was originally developed as an antidepressant, but it has been shown to work well for quitting smoking in people with and without a history of depression. Bupropion makes it roughly two times more likely for someone to have a successful quit, as compared to not taking any quit medication.
Medical review: Nathan Cobb, MD, September 26, 2017
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.