The most common side effects are trouble sleeping and dry mouth. If you’re having trouble sleeping, try taking your evening dose in the late afternoon or early evening, rather than at bedtime. But be sure that at least 8 hours have passed since your morning dose.
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.