Weight Loss Effects of Bupropion
Bupropion treatment is associated with a modest average weight loss of 2.77 kg (6.1 pounds) over 6-12 months of treatment. 1
Evidence on Bupropion and Weight Loss
Bupropion (Wellbutrin) has demonstrated consistent but modest weight loss effects across multiple studies. According to the American College of Physicians clinical practice guideline, a pooled analysis of three studies showed that bupropion-treated patients achieved an average weight loss of 2.77 kg over 6-12 months 1.
Key findings about bupropion and weight loss:
Population characteristics: Studies primarily included adults with an average age of 43 years, with women representing 81% of participants and an average baseline weight of 94.3 kg 1
Treatment context: Most studies (two out of three) included dietary interventions alongside bupropion, and one study included exercise as a co-intervention 1
Dosage considerations: Higher doses appear to produce greater weight loss effects, with bupropion SR 400 mg/day showing more significant results than 300 mg/day in controlled trials 2
Comparative Effectiveness
When comparing bupropion to other weight loss medications:
Bupropion (2.77 kg at 6-12 months) produces less weight loss than:
Bupropion produces similar weight loss to:
Clinical Trial Results
More recent research has shown potentially greater weight loss with bupropion in specific controlled settings:
In a 48-week double-blind trial, participants completing 24 weeks of treatment achieved weight losses of 7.2% and 10.1% of initial body weight with bupropion SR 300 mg/day and 400 mg/day, respectively 2
Another study of overweight and obese women showed that bupropion responders who completed 24 weeks achieved weight loss of 12.9% ± 5.6% 4
However, these more dramatic results from individual trials should be interpreted cautiously, as the pooled analysis from clinical practice guidelines represents a more reliable estimate across multiple studies
Bupropion as Part of Combination Therapy
Bupropion is also used in combination with naltrexone (Contrave) for weight management:
Bupropion/naltrexone SR produces approximately 4.2-5.2% weight loss at 1 year 1
Participants who achieve ≥5% weight loss by week 16 with naltrexone/bupropion are likely to maintain clinically significant weight loss after 1 year of treatment 5
Monitoring and Discontinuation
When using bupropion for weight loss:
- Evaluate weight loss progress at regular intervals
- Consider discontinuing therapy if clinically meaningful weight loss (typically ≥5%) is not achieved within 3-4 months 1
- Monitor for common side effects including nausea, headache, constipation, dizziness, and insomnia
Clinical Implications
Bupropion may be a reasonable option for weight management in patients who:
- Have contraindications to other weight loss medications
- Would benefit from its antidepressant effects alongside weight management
- Need an alternative when first-line weight loss medications are not tolerated
However, medications specifically approved for weight management (such as phentermine/topiramate, liraglutide, or semaglutide) generally produce greater weight loss and should be considered first when appropriate for the patient.