Naltrexone / Bupropion ER
A twice-daily tablet that targets hunger and food cravings
Brand names: Contrave
Quick read · 5 min
People who tend to consider this:
- ✓Struggle with emotional or compulsive eating
- ✓Prefer a pill rather than an injection
- ✓Want modest weight loss with potential mood-related advantages
This may not be right if:
- ✕You have a seizure disorder
- ✕You currently use opioid medications
- ✕You have an eating disorder
- ✕You want the highest weight loss available
Not a complete list. Whether this treatment is right for you depends on factors only your doctor can assess.
Weight loss — what trials show
In the COR-BMOD trial (56 weeks, combined with behavioural therapy), people lost an average of about 9.3% of their body weight — roughly 20 lbs for a 220 lb person. A separate trial without behavioural therapy showed about 6.1% weight loss — suggesting this drug works best alongside lifestyle changes. About 39–55% of participants lost 5% or more of their body weight across the trials.
These are averages from clinical trials — individual results vary. Trials compare the drug against a dummy pill, not against other weight loss drugs.
See the full trial data →How this compares
Average weight loss in clinical trials. Not a ranking — individual results vary.
Averages from clinical trials at highest approved dose. Not everyone achieves these results.
What to expect — week by week
The dose is stepped up over 4 weeks to the full therapeutic level.
Most people notice reduced hunger and fewer food cravings around this point.
Appetite and craving changes typically within 4–8 weeks; significant weight loss by 16–24 weeks
Most weight loss has occurred. Continued benefit with ongoing treatment.
What happens if you stop?
Weight regain after stopping is expected. The drug must be tapered — stopping abruptly can cause withdrawal from the bupropion component.
Weight trajectory — during treatment and after stopping
Pattern estimated — no large randomised withdrawal trial published for this drug.
Most of the lost weight returns within a year of stopping — this is the body returning to its defended weight, not a failure. Long-term use or maintenance therapy can help preserve results.
Side effects
Frequencies from COR-I. Most stomach and gut side effects are mild-to-moderate and peak during the dose increase period (first 12–16 weeks).
Percentages from COR-I. Source: trial publication.
- •Bupropion lowers the seizure threshold — do not take if you have a seizure disorder or have had a seizure. Avoid if you drink alcohol heavily, as this further increases seizure risk.
- •Do not take this drug if you currently use any opioid medication (including codeine, tramadol, or opioid cough medicines) — it will trigger acute withdrawal.
- •Bupropion carries a boxed warning about increased suicidal thoughts in people under 25. Discuss your mental health history with your doctor before starting.
This is not a complete list. Your doctor can advise based on your full medical history.
Muscle and lean mass
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.
What does the lost weight consist of?
Resistance training (weight lifting, bodyweight exercises) can significantly reduce the lean mass portion. Aim for 2–3 sessions per week during weight loss.
Proportions estimated — detailed body composition data not available from published trials for this drug.
Cost & access
~$100–$400/month (brand). Generic available in some markets.
Requires a prescription from a licensed healthcare provider. Prices vary. Ask your doctor about savings programs.
~$100–$400/moper month (list price)
Some generic options available. Manufacturer savings programs may apply — ask your pharmacist.
How to take it
- •Take with food — twice daily, morning and evening
- •Dose is increased gradually over the first 4 weeks to reduce side effects (start with 1 tablet in the morning)
- •Swallow tablets whole — do not crush, chew, or break them
- •Do not stop suddenly — the dose should be tapered under medical supervision
How it works
Bupropion activates appetite-suppressing nerve cells in the brain's hunger control centre (the hypothalamus). Naltrexone blocks the feedback signal that would normally switch this effect off — letting bupropion's appetite-reducing action last longer. Together they reduce hunger and the brain's reward response to food, which may be particularly useful for people who struggle with food cravings.
Cardiovascular & other benefits
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.
- ✓May help specifically with emotional eating and food cravings
- ✓Bupropion's antidepressant effect may be beneficial if low mood contributes to overeating
- ✓Oral twice-daily pill — no injection required
Community insights
These are personal experiences shared in public online communities — not medical advice.
“Nausea is worst in the first 2–4 weeks. Taking it with food — especially for the evening dose — helps significantly.”
“If you use any opioid medications (including codeine cough syrup or tramadol), you cannot take this drug — the naltrexone will block them and can cause withdrawal.”
Common questions
After reading this page, most people compare this with other medications, check if they qualify, or learn about side effects in more detail.
Next step most people take
Based on clinical trials · No rankings · Every claim linked to source
Last reviewed: March 2026