Skip to main content

What's the difference between Wellbutrin XL and SR?

Medically reviewed by Melisa Puckey, BPharm. Last updated on Aug 18, 2022.

Official answer

by Drugs.com

Wellbutrin XL and Wellbutrin SR both contain the same active ingredient which is bupropion.

Differences between Wellbutrin XL and Wellbutrin SR

The difference between Wellbutrin XL and Wellbutrin SR is how quickly they are released and then absorbed into the body. Wellbutrin XL is an extended release tablet which releases more slowly than the Wellbutrin SR tablet which is released faster.

Another difference is that Wellbutrin SR is only used for major depressive disorder (MDD), whereas Wellbutrin XL can be used for both MDD and seasonal affective disorder (SAD). SAD is depression that occurs mainly in the fall and winter.

What is Bupropion?

Bupropion, the active ingredient in this medicine, is an antidepressant medication that works by changing the levels of chemicals in the brain.

Dosing of Wellbutrin XL and Wellbutrin SR

You should not change between Wellbutrin XL and SR on your own. Your doctor may switch formulations depending on your diagnosis and response to treatment.

The dose for Wellbutrin XL starts at 150 mg once per day, and may go up to 300 mg once per day. The dose is the same for both major depressive disorder and SAD. The daily dose is usually taken in the morning.

Wellbutrin SR is only approved to treat major depressive disorder. The dose starts at 150 mg once per day and may gradually increase to 150 mg twice per day. A maximum dose of 200 mg twice per day may be given if you haven't responded well to the 150 mg twice per day dose, and your doctor thinks it is needed. Wellbutrin SR is usually taken in the morning and mid-afternoon.

If you miss a dose of Wellbutrin SR, you should take it as soon as you remember and then continue with your usual dose schedule. However, because Wellbutrin XL is an extended-release medication, if you miss a dose, do not take it when you remember. Take it the next day at the usual time.

Do not stop taking Wellbutrin SR or XL on your own. Talk to your health care provider first.

Summary

Wellbutrin XL

  • Extended release form
  • Usually taken once daily
  • Used for major depressive disorder (MDD)
  • Used for seasonal affective disorder (SAD)

Wellbutrin SR

  • Usually taken twice daily
  • Use for major depressive disorder (MDD)
References
  1. National Alliance on Mental Illness (NAMI). Bupropion (Wellbutrin). December 2020. Available at: https://www.nami.org/About-Mental-Illness/Treatments/Mental-Health-Medications/Types-of-Medication/Bupropion-(Wellbutrin). [Accessed March 2, 2021].
  2. Food and Drug Administration (FDA). Wellbutrin XL Prescribing Information. May 2017. Available at: https://www.accessdata.fda.gov/drugsatfda_docs/label/2017/021515s036lbl.pdf. [Accessed March 2, 2021].
  3. Food and Drug Administration (FDA). Wellbutrin SR Prescribing Information. October 2020. Available at: https://gskpro.com/content/dam/global/hcpportal/en_US/Prescribing_Information/Wellbutrin_SR/pdf/WELLBUTRIN-SR-PI-MG.PDF. [Accessed March 2, 2021].

Drug information

Related support groups

Medical Disclaimer