Bupropion HCL (Wellbutrin)

  • Generic name: Bupropion hcl
  • Brand names: Wellbutrin SR, Wellbutrin XL, Zyban
  • Therapeutic class: Antidepressant, Norepinephrine and Dopamine Reuptake Inhibitor

What is Wellbutrin used for?

  • Depression. Bupropion hcl is a prescription antidepressant with very distinct dopaminergic activity and may be very useful for depression accompanied with hypersomnia and fatigue. Persons who experience apathy, poor attention, and lack of motivation may do well with Wellbutrin.
  • Seasonal affective disorder (recurring fall/winter onset of depressive symptoms)
  • Smoking cessation

How long until Wellbutrin works?

You may notice improvement in depression after 2 or 3 weeks1. And you should wait for 6-8 weeks for its full antidepressant effect.

What time of day to take Wellbutrin XL?

Best to take Wellbutrin XL is in the morning because it is activating and tends to keep people awake at night. But if you experience fatigue, try to take it at night. Bupropion SR is taken two times per day.

Difference between Wellbutrin SR and Wellbutrin XL

Both formulations SR and XL contain the same active medicine bupropion hcl. The main difference is how the medicine is released into the system and the time it takes for the body to digest and process it. Sustained-release (Wellbutrin SR) needs to be taken twice daily and extended-release (Wellbutrin XL) - once daily.

In general the slower release forms are better for most people, so XL will be better than SR and SR is better than immediate release. But not always.

The XL form is safer and better tolerated, than SR form, but is more expensive, so the benefits may be negated by cost issues.

Wellbutrin benefits

Bupropion is less likely to affect sexual desire and opportunities. Moreover, it can increase libido and intensity of orgasm.

Another significant advantage is that the long-term treatment doesn't contribute to extra pounds. Sluggish and obese persons as well as smokers and ADHD sufferers may benefit from the energizing and anti-craving properties of bupropion. Recent 2013 study found that bupropion may help overweight women to lose weight2.

Bupropion is a good choice for lethargic or fatigued persons. On the other hand, it is not a perfect option for anxious and agitated persons, who may be particularly vulnerable to its stimulating properties.


  • History of seizures, epilepsy, or eating disorder (e.g. bulimia or anorexia nervosa).
  • Patients undergoing abrupt discontinuation of alcohol or benzodiazepines.
  • Use of monoamine oxidase (MAO) inhibitors.

Serious drug interactions

  • Antipsychotic drugs (e.g., haloperidol, risperidone, thioridazine) - increased risk of seizures. Use with extreme caution.
  • MAO inhibitors - concurrent administration is contraindicated.
  • Theophylline -- increased risk of seizures. Use with extreme caution.

Further reading


  • 1. Preskorn SH, Othmer SC. Evaluation of bupropion hydrochloride: the first of a new class of atypical antidepressants. Pharmacotherapy. 1984 Jan-Feb;4(1):20-34.
  • 2. White MA1, Grilo CM. Bupropion for overweight women with binge-eating disorder: a randomized, double-blind, placebo-controlled trial. J Clin Psychiatry. 2013 Apr. PubMed
  • 3. Haas JS, Kaplan CP, Barenboim D, Jacob P 3rd, Benowitz NL. Bupropion in breast milk: an exposure assessment for potential treatment to prevent post-partum tobacco use. Tob Control. 2004 Mar;13(1):52-6. PubMed
  • 4. Chun-Fai-Chan B, Koren G, Fayez I, Kalra S, Voyer-Lavigne S, Boshier A, Shakir S, Einarson A. Pregnancy outcome of women exposed to bupropion during pregnancy. Am J Obstet Gynecol. 2005 Mar;192(3):932-6. PubMed

Author: OriginalDrugs Team
Last reviewed: May, 2015

Advanced Consumer Info
wellbutrin xl
bupropion hcl
  • Pregnancy Risk Factor: C. Available data suggest that bupropion does not increase the rates of malformation above baseline4.
  • Breastfeeding:Bupropion is excreted into breast milk. Research indicates that the dose of bupropion that would be delivered to an infant of a woman taking a therapeutic dose of bupropion is small3.
  • Mechanism of action: Bupropion works by inhibiting the re-uptake of neurotransmittes norepinephrine and dopamine neurotransmission without any significant direct effects on serotonin.
  • Soon after its release, Wellbutrin was temporarily removed from the market due to the occurrence of seizures in some patients. However, further investigation showed that seizures were primarily associated with high doses (above the current recommended maximum of 450 mg/day), a history of seizures or brain trauma, or excessive alcohol use.
  • False-positive for amphetamine.
    Bupropion, an active ingredient of Wellbutrin XL, has a structure similar to stimulants, and may cause urinary tests to read a positive result in both amphetamines and occasionally, methamphetamine categories.