Does Wellbutrin Cause Weight Gain?

Weight changes are a known potential side effect of antidepressants, including Wellbutrin (bupropion). Clinical trials report mixed results:

• Wellbutrin XL (150–300 mg daily): 23% lost at least 5 pounds, 11% gained over 5 pounds
• Wellbutrin SR (300 mg daily): 14% lost over 5 pounds; (400 mg daily): 19% lost over 5 pounds
• In those same SR studies, 3% (300 mg) and 2% (400 mg) gained weight

Another trial combining Wellbutrin with diet and exercise showed obese adults lost 7–10% of body weight over 24 weeks. Although not FDA‑approved for weight loss, bupropion is sometimes used off‑label in weight management programs. Individual responses vary, so discuss any concerns with your healthcare provider.

How Wellbutrin May Lead to Weight Loss

• Appetite suppression through increased dopamine and norepinephrine levels
• Higher energy levels, encouraging more physical activity
• Improved mood and motivation for healthy lifestyle changes
• Possible metabolic effects that favor weight reduction

Note that not everyone experiences weight loss on Wellbutrin.

Other Antidepressants and Weight Gain

Certain antidepressant classes are more likely to cause weight gain:

• Tricyclics (nortriptyline, amitriptyline) and MAOIs (tranylcypromine, phenelzine)
• SSRIs over long-term use (especially paroxetine; also fluoxetine, sertraline, citalopram, escitalopram)
• SNRIs (venlafaxine, duloxetine) can cause gain or loss depending on the person

Approved Uses of Wellbutrin

• Major depressive disorder
• Seasonal affective disorder
• Smoking cessation aid (reduces nicotine cravings)

Off‑label uses include ADHD, bipolar depression, obesity adjunct, and treatment of SSRI-induced sexual dysfunction.

Mechanism of Action

Wellbutrin is a norepinephrine-dopamine reuptake inhibitor (NDRI). It raises levels of these neurotransmitters to alleviate depression. For smoking cessation, it likely reduces nicotine craving by altering brain chemistry.

Side Effects of Wellbutrin

• Common: headache, dry mouth, nausea, insomnia, sore throat, taste changes, constipation, increased sweating, weight changes
• Serious: seizure risk (dose‑dependent), high blood pressure, suicidal thoughts (especially under age 24), allergic reactions, mania or hypomania, worsening glaucoma, sexual dysfunction (lower risk than other antidepressants)

Precautions Before Starting Wellbutrin

Inform your provider about any of the following:

• History of seizures or eating disorders
• Head injury or central nervous system tumors
• Glaucoma
• Heart disease or high blood pressure
• Diabetes or bipolar disorder
• Alcohol or substance use history
• Kidney or liver disease
• Pregnancy or breastfeeding plans

Sources

• Anderson JW et al. Bupropion SR Enhances Weight Loss. Obes Res. 2002;10:633–641.
• Sanchez C et al. Comparative review of SSRIs. Int Clin Psychopharmacol. 2014 Jul;29(4):185–196.
• Cantú TG, Korek JS. MAOIs and weight gain. Drug Intell Clin Pharm. 1988 Oct;22(10):755–759.
• Berken GH et al. Weight gain with TCAs. J Affect Disord. 1984 Oct;7(2):133–138.
• Bupropion hydrochloride drug summary. Prescribers’ Digital Reference. Accessed Apr 1, 2025.
• Bupropion (Rx). Medscape. Accessed Apr 1, 2025.