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What does it do?

Naltrexone and bupropion is used to help you lose weight by reducing your appetite.

Before you start

  • Tell your doctor if you have kidney problems, bipolar disorder, or if you have ever had a seizure.
  • Tell your doctor if you are taking opioids (e.g. fentanyl, morphine, oxycodone).
  • Tell your doctor if you are pregnant, planning to become pregnant, or breastfeeding.

How should you take it?

Take naltrexone and bupropion regularly as directed with a glass of water. Swallow the tablets whole. You can take it with or without food.

What if you forget a dose?

If it is nearly time for your next dose, skip the missed dose and take your next dose at the usual time. Otherwise, take the missed dose as soon as you remember. Do not take two doses at the same time.

Can you take other medicines?

Tell your pharmacist or doctor about all medicines or treatments that you may be taking, including vitamins, herbal products (e.g. St John's wort) or recreational drugs (e.g. heroin, ecstasy).

What side effects might you notice?

Side EffectsRecommended action


Suicidal thoughts

Tell your doctor immediately

Trouble concentrating, mood changes

Tell your doctor

Trouble sleeping


Headache, dizziness, ringing in the ears

Dry mouth, changes in taste

Nausea, vomiting, constipation

Tell your doctor if troublesome

If you notice any other effects, discuss them with your doctor or pharmacist.

Other information:

  • Naltrexone and bupropion can impair your ability to do tasks such as driving or using machines. Alcohol makes this worse. Discuss your risk with your health professional. (search NZTA - Are you safe to drive?)
  • After you have stopped taking naltrexone, you may be more sensitive to opioids and have a higher risk of overdose if you start using them again.

This leaflet contains important, but not all, information about this medicine.

Prepared by the MyMedicines Committee at Christchurch Hospital, Te Whatu Ora - Waitaha, New Zealand. June 2024

For more general information about this sheet and its contents, see: What does a My Medicines sheet cover?

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About My Medicines

My Medicines Patient Information Leaflets (PILs) contain important, but not all, information about the medicines they describe.

For more information about the sheets, see: What does a My Medicines sheet cover?

My Medicines is developed by a team at Te Whatu Ora – Waitaha. Our team is made up of doctors, pharmacists, and a non-medical person to help us keep to plain language. We also discuss our information with specialist health professionals or groups when needed