NZ Formulary

Norethisterone (5 mg tablet)


What does it do?

Norethisterone is used to treat irregular, painful or heavy periods, premenstrual syndrome (PMS) and endometriosis. It may also be used to delay periods.

How should you take it?

Take norethisterone as directed with a glass of water.

What if you forget a dose?

Take the missed dose as soon as possible. If it is close to the time for your next dose, skip the missed dose and carry on as normal. 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.

What side effects might you notice?

Side EffectsRecommended action

Symptoms of a blood clot including: sudden shortness of breath, swelling or pain in one leg

Symptoms of a stroke including: sudden weakness of the face, arm or leg, especially on one side, face drooping, sudden changes in vision or speech, sudden loss of balance

Severe headache

Chest pain

Tell your doctor immediately

Changes in periods

Mood changes, headache

Sore breasts

Weight gain

Brown patches on the face

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 heart, liver or gallbladder problems, migraines, or high blood pressure.
  • Tell your doctor if you have had a blood clot or stroke, or if you smoke.
  • Women taking norethisterone may have a small increased risk of breast cancer. Tell your doctor if you, or someone in your family, has ever had breast cancer.
  • Tell your doctor if you are pregnant, planning to become pregnant, or breastfeeding.