Naltrexone / Bupropion ER — Clinical Evidence
All published trials referenced on this site. Click any source link to read the original journal article.
Last reviewed: March 2026
Medical disclaimer: This website is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare provider before starting, stopping, or changing any treatment.
Randomised controlled trials
In the following trials, participants were randomly assigned to Naltrexone / Bupropion ER or a dummy pill (placebo). All weight loss figures are average body weight reductions from baseline.
| Trial | Key result | Source |
|---|---|---|
| [1]COR-I | 6.1% mean weight loss at full dose (32/360 mg) vs. 1.3% placebo. 48% achieved ≥5% loss vs. 16% placebo. Nausea 33%, constipation 19%, headache 18%. | The Lancet 2010 ↗ |
| [2]COR-BMOD (with intensive behaviour therapy) | 9.3% mean weight loss with drug + behaviour therapy, vs. 5.1% with placebo + behaviour therapy — demonstrating additive benefit of combining drug with structured lifestyle change. | Obesity 2011 ↗ |
Reported side effects
Frequencies from COR-I. View source ↗
| Side effect | Frequency in trial |
|---|---|
| Nausea | 33% |
| Constipation | 19% |
| Headache | 18% |
| Vomiting | 11% |
| Dizziness | 10% |
| Dry mouth | 8% |
Body composition data
No specific body composition data published for the obesity indication. Lean mass outcomes depend largely on dietary protein and exercise during the calorie deficit produced.
Cardiovascular & metabolic data
The LIGHT cardiovascular outcomes trial was terminated early due to a protocol violation and did not provide a definitive answer on CV outcomes. Slight blood pressure increases are observed — requires monitoring.