How To Use Mysimba Tablets
Table of Contents
Mysimba (naltrexone/bupropion) is a prescription medication for weight loss in adults with obesity. Contains 8mg naltrexone and 90mg bupropion per tablet.
Key Takeaways
- Dosing: 4-week escalation to maintenance dose (2 tablets twice daily)
- Administration: Swallow whole with water - do not crush/chew
- Timing: Morning and evening doses (avoid evening dose if insomnia occurs)
- Discontinuation: Gradual tapering recommended
- Effectiveness: Assess after 16 weeks - discontinue if <5% weight loss
Mysimba provides effective weight management through a carefully controlled dosing schedule designed to minimize side effects while maximizing effectiveness.
Mysimba Dosage Schedule
Week 1: Initial Dose
1 tablet in morning for first 7 days
Week 2: Increased Frequency
1 tablet morning and evening for next 7 days
Week 3: Further Increase
2 tablets morning and 1 tablet evening for next 7 days
Week 4: Maintenance Dose
2 tablets twice daily (maximum 2 tablets per dose, 4 tablets daily)
Important: This gradual escalation helps minimise side effects. Do not exceed maximum daily dose of 4 tablets (32mg naltrexone/360mg bupropion).
How To Take Mysimba Tablets
Correct Administration
- Swallow tablets whole with water
- Take with food to reduce nausea
- Morning dose: With breakfast
- Evening dose: Before 6pm (to prevent insomnia)
- Space doses at least 8 hours apart
Avoid These Common Mistakes
| Mistake | Risk | Correct Approach |
|---|---|---|
| Crushing/chewing tablets | Rapid release causing side effects | Swallow whole |
| Taking with high-fat meal | Increased bupropion absorption | Take with light meal |
| Late evening dose | Insomnia | Take before 6pm |
Important Precautions
- Uncontrolled hypertension
- Seizure disorder
- Eating disorder (bulimia/anorexia)
- Severe liver cirrhosis
- Concurrent use of monoamine oxidase inhibitors (MAOIs)
Monitoring Requirements
- Blood pressure: Check weekly for first 3 months
- Weight: Assess after 16 weeks - discontinue if <5% loss
- Mental health: Monitor for mood changes/suicidal thoughts
Missed Dose Instructions
| Situation | Action |
|---|---|
| Missed morning dose | Take as soon as remembered if <8hrs until evening dose |
| Missed evening dose | Skip and resume next morning |
| Missed ≥2 doses | Restart at previous tolerated dose |
Never double dose to make up for a missed tablet - this increases seizure risk.
FAQs
Can I drink alcohol while taking Mysimba?
Avoid alcohol - it lowers seizure threshold and increases dizziness risk. The NHS recommends no more than 1-2 units occasionally, spaced away from doses.
Why must the tablets be swallowed whole?
The modified-release coating controls drug absorption. Crushing causes rapid release, potentially leading to seizures (bupropion) or severe nausea (naltrexone).
What if I don't lose 5% weight in 16 weeks?
NICE guidelines recommend discontinuation as you're unlikely to achieve clinically meaningful weight loss. Your doctor will suggest alternative therapies.
Can I take Mysimba while breastfeeding?
No - bupropion passes into breast milk. The MHRA advises against breastfeeding during and for 7 days after treatment.
How should I store Mysimba tablets?
Keep in original packaging at room temperature (below 25°C). The desiccant packet in the bottle should remain - it prevents moisture damage to the tablets.
Ready to Start Your Weight Loss Journey?
If you're struggling to lose weight through diet and exercise alone, our UK-registered doctors can help determine if Mysimba Tablets is appropriate for your condition through a confidential online consultation.
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Medical Content Manager
Nabeel is a co-founder and medical content manager of Chemist Doctor. He works closely with our medical team to ensure the information is accurate and up-to-date.
Medical Doctor
Dr. Talal is a GMC registered doctor and medical reviewer at Chemist Doctor. He ensures clinical accuracy and reliability across health content.
Medical Director
Usman is a co-founder and medical director of Chemist Doctor. He leads the organisation's strategic vision, bridging clinical and operational priorities.
Review Date: 18 November 2025
Next Review: 20 May 2026
Published on: 18 November 2025
Last Updated: 19 November 2025
