NZ Formulary



What does it do?

Carbimazole is used to reduce the amount of hormone made by your thyroid gland.

How should you take it?

Take carbimazole regularly as directed with a glass of water.

What if you forget a dose?

Take the missed dose as soon as possible and continue as directed.

Can you take other medicines?

Some medicines available without a prescription may react with carbimazole including:

  • iodine supplements (e.g. Iodine/Lugol’s solution®)

Tell your pharmacist or doctor about all medicines or treatments that you may be taking including vitamins, herbal products (e.g. kelp powder) or recreational drugs. Avoid foods such as seaweed or kelp that may contain iodine.

What side effects might you notice?

Side EffectsRecommended action

Reduced number of blood cells that fight infections or help your blood to clot - symptoms include: fever, chills, sore throat or generally feeling unwell, or easy or unusual bruising or bleeding

Symptoms of liver problems including: yellow skin or eyes, itching, dark urine, pale bowel motions, abdominal pain

Tell your doctor immediately


Hair loss or thinning

Joint, muscle or bone aches and pains

Stomach upset

Tell your doctor if troublesome

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

Other information:

  • Tell your doctor if you have liver problems, or a blood disorder.
  • Women should use reliable contraception while taking carbimazole. If you plan to get pregnant, or find you are pregnant, contact your doctor. Tell your doctor if you are breastfeeding.