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Contrave (Naltrexone/Bupropion)

Metabolicprescriptionoral · inferred

Fixed-dose combination of sustained-release naltrexone 8 mg + bupropion 90 mg per tablet, approved for chronic weight management as adjunct to diet/exercise in adults with BMI >=30 or >=27 with weight-related comorbidity. Titration: 1 tab QAM week 1, then 1 tab BID week 2, then 2 tabs AM + 1 PM week 3, then 2 tabs BID (maintenance, 32 mg naltrexone + 360 mg bupropion daily) from week 4. Bupropion dominates plasma PK (t1/2 ~21h); naltrexone t1/2 ~4h but active metabolite 6-beta-naltrexol contributes. Contraindicated with uncontrolled HTN, seizure disorders, anorexia/bulimia, chronic opioid use (precipitates withdrawal), MAOIs. Modest mean weight loss ~4-5% over placebo at 1 year.

Projected serum levels — 1 pill (≈ 98 mg), twice daily

Contrave (Naltrexone/Bupropion)
Contrave (Naltrexone/Bupropion) modeled serum levels, 1 pill (≈ 98 mg) twice daily over 15 days Population-based pharmacokinetic estimate. Steady state reached after approximately 1 days. 0 12.5 25 37.5 50 Day 0 Day 4 Day 7 Day 11 Day 15 Time on a regular schedule ≈ steady state · day 1
Contrave (Naltrexone/Bupropion) modeled serum levels with a loading dose of 1.3 pill, then 1 pill (≈ 98 mg) twice daily The first dose is larger so levels approach steady state faster. 0 12.5 25 37.5 50 Day 0 Day 4 Day 7 Day 11 Day 15 Time on a regular schedule

Maintenance schedule: 1 pill (≈ 98 mg) twice daily (oral).

Loading schedule: 1.3 pill on day 1, then 1 pill (≈ 98 mg) twice daily — reaching therapeutic levels sooner.

Modeled steady state after ~1 days: peak ≈ 44.9 mg, trough ≈ 12.5 mg body load. Population-based estimate over 15 days for a reference dose at a 70 kg reference body mass — the interactive app scales curves to your doses, timing, and body mass.

Key facts

Category
Metabolic
Route modeled
Oral
Model confidence
inferred
Half-life
4.9 h
Common dose
1 pill (≈ 98 mg)
Suggested maximum
4 pill/day
Reference dose range
0.50–4 pill (single dose)
Suggested cadence
twice daily

Documented interactions

  • danger
    4-MMC (Mephedrone) + Contrave (Naltrexone/Bupropion) CYP inhibition

    Contrave (Naltrexone/Bupropion) reversible_inhibitor of CYP2D6 predicted to change 4-MMC (Mephedrone) AUC by ~2.27x

  • danger
    6-APB (Benzofury / 6-(2-aminopropyl)benzofuran) + Contrave (Naltrexone/Bupropion) CYP inhibition

    Contrave (Naltrexone/Bupropion) reversible_inhibitor of CYP2D6 predicted to change 6-APB (Benzofury / 6-(2-aminopropyl)benzofuran) AUC by ~3.33x

  • danger
    Amphetamine (Adderall) + Contrave (Naltrexone/Bupropion) CYP inhibition

    Contrave (Naltrexone/Bupropion) reversible_inhibitor of CYP2D6 predicted to change Amphetamine (Adderall) AUC by ~2.11x

  • danger
    Atomoxetine (Strattera) + Contrave (Naltrexone/Bupropion) CYP inhibition

    Contrave (Naltrexone/Bupropion) reversible_inhibitor of CYP2D6 predicted to change Atomoxetine (Strattera) AUC by ~2.68x

  • danger
    Bupropion (Wellbutrin) + Contrave (Naltrexone/Bupropion) Stacked effects

    Bupropion (Wellbutrin) and Contrave (Naltrexone/Bupropion) both push the DAT, NET, and nicotinic ACh neuronal in the same direction.

  • danger
    Dextromethorphan (DXM) + Contrave (Naltrexone/Bupropion) CYP inhibition

    Contrave (Naltrexone/Bupropion) reversible_inhibitor of CYP2D6 predicted to change Dextromethorphan (DXM) AUC by ~2.47x

Serum checks 82 modeled interaction pairings for contrave (naltrexone/bupropion) across your whole stack — absorption conflicts, enzyme inhibition, and nutrient depletion included.

Research behind this entry

  1. Effect of naltrexone plus bupropion on weight loss in overweight and obese adults (COR-I) Greenway FL et al. · Lancet, 2010 DOI

    Pivotal 1742-patient phase 3 RCT: NB32 (naltrexone 32 mg + bupropion 360 mg) achieved 6.1% weight loss vs 1.3% placebo at 56 weeks; supported initial regulatory approval.

  2. A randomized, phase 3 trial of naltrexone SR/bupropion SR on weight and obesity-related risk factors (COR-II) Apovian CM et al. · Obesity, 2013 DOI

    Confirmatory 1496-patient phase 3 trial: NB32 produced 6.4% weight loss vs 1.2% placebo at week 28 with improvements in cardiometabolic risk factors.

2 published studies referenced in the app, each with a plain-language summary.