What it is used for

Delaying a period (for example, for a holiday)
Heavy or irregular periods
Endometriosis
Contraception (lower dose progestogen-only pill)
Part of some hormone replacement therapy (HRT)

Read our guides:

Endometriosis

Off-label uses

Doctors sometimes prescribe a medicine for a condition it is not officially licensed for. This is called off-label use. It is legal and common when there is good evidence it helps, and your doctor should explain why they are suggesting it.

Norethisterone is not commonly used off-label.

How it works

Norethisterone is a man-made version of progesterone. It keeps the lining of the womb stable, which stops it shedding and so delays or controls bleeding. Over time, it can also shrink patches of endometriosis.

Side effects

Like all medicines, Norethisterone can cause side effects, although not everyone gets them. Many are mild and ease after the first few weeks.

Common side effects

bloating
breast tenderness
headache
feeling sick
mood changes
spotting or irregular bleeding

Tell your doctor or pharmacist if these bother you or do not go away.

Serious side effects

These are rare. Call 111 or contact your doctor straight away if you get:

pain, swelling or warmth in one leg, chest pain or sudden breathlessness, which can be signs of a blood clot. Call 999
a sudden severe headache or problems with vision or speech
yellowing of the skin or eyes

Call 999 if you have signs of a serious allergic reaction, such as swelling of your lips, mouth, throat or tongue, or trouble breathing.

You can report any side effect to the Yellow Card scheme, run by the medicines regulator.

Stopping and withdrawal

Important safety information

Higher doses used to delay periods are not a contraceptive.
It is not suitable if you have had a blood clot, unless a specialist advises it.

Questions about your medicine?

A pharmacist can answer questions about your medicines for free, without an appointment. You can also ask your GP for a medication review. Check if you can get free prescriptions.