Norethisterone for Period Delay

Norethisterone is progesterone medicine, similar to the natural female hormone progesterone. It is the only progesterone licenced in the UK for delaying menstrual bleeding. This can be helpful during holidays, travel, or important life events.

Norethisterone may not be suitable for everyone, for example if you have breast cancer or a history of blood clots. Our clinicians will review your medical records before prescribing norethisterone to ensure it is safe for you. However, please inform the surgery of any changes to your health or if you have any concerns before starting treatment.

Norethisterone should be started 3 days before your period is due and you can stop it when you are happy to have a bleed. It is normally prescribed to delay a period by a maximum of 17 days.

The usual dosage is one 5mg tablet three time daily.

Please note: How well norethisterone works varies and it may not completely prevent bleeding in all cases. Your period should arrive 2 or 3 days after you stop taking norethisterone.
No, norethisterone does not act as a contraceptive when used to delay periods. You can still become pregnant whilst taking it. If contraception is needed, please use additional protection such as condoms.
Some women may experience slightly heavier bleeding after stopping norethisterone, but this varies from person to person and is likely resolve with time.
Norethisterone causes a slightly increased risk of blood clots, although the risk is generally considered low when used short-term. Before prescribing, one of our clinicians will assess your individual risk. If you are considered high-risk, an alternative treatment may be recommended.

Side Effects

Other side effects are generally unusual. Some possible side effects are:

  • Menstrual cycle irregularities
  • Spotting bleeding
  • Dizziness
  • Headache
  • Nausea
  • Low sex drive

Rare but serious side effects include:

  • Blood clots
  • Liver issues/jaundice
  • Allergic reactions

If you experience any chest pain, shortness of breath, sudden vision changes, pain, tenderness or swelling in your calf, ankle or foot or the skin of your leg becomes discoloured, red or and warm to touch whilst taking norethisterone, seek medical attention immediately. 

If you would like request a prescription for norethisterone or another medication to delay your period, please fill in the online request form.