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Norethisterone for painful or heavy periods

Primolut N, Utovlan

Norethisterone is a female hormone treatment.

The usual dose is one tablet either two or three times daily. You may be asked to take the tablets regularly each day, or just to take them on certain days of the month.

The most common side-effects are feeling bloated, feeling sick (nausea), and headache. These are generally mild in nature.

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About norethisterone

Type of medicine

Progestogen (female hormone)

Used for

Painful or heavy periods, particularly when associated with endometriosis

Also called

Norethindrone (in US); Primolut N®, Utovlan®

Available as


Norethisterone is a man-made form of progesterone, a naturally occurring female sex hormone. It is referred to as a progestogen and it has a number of uses. Low doses are used to prevent pregnancy, or as hormone replacement therapy (HRT). Medium-strength tablets (5 mg) such as Primolut N® and Utovlan® are used to treat heavy and painful periods particularly if they are associated with a condition called endometriosis. Higher doses are used in the treatment of some female cancers, such as breast cancer.

This leaflet discusses norethisterone when it is used to treat painful or heavy periods associated with endometriosis. Endometriosis is a condition where tissue which is normally only found inside the womb (uterus), becomes 'trapped' in other parts of the body, often in the pelvic area or lower abdomen. This causes symptoms such as painful and heavy periods. Treatment aims to reduce the pain and amount of blood loss. Norethisterone can also be considered for heavy periods not associated with endometriosis, although other treatment options are more commonly prescribed for this.

There are a number of other medicine leaflets which will give you more information about norethisterone if you are taking it for contraception or as HRT. These are: Progestogen-only contraceptive tablets, Norethisterone contraceptive injection, Combined hormonal contraceptives and Oestrogen and progestogen for HRT.

Before taking norethisterone

Some medicines are not suitable for people with certain conditions, and sometimes a medicine can only be used if extra care is taken. For these reasons, before you start taking norethisterone it is important that your doctor knows:

  • If you are pregnant or breastfeeding.

  • If you have any problems with the way your liver works, or any kidney problems.

  • If you have heart or blood vessel problems, or if you have ever had a blood clot in an artery or vein.

  • If you have any of the following: diabetes, epilepsy, migraines, high blood pressure (hypertension), or asthma.

  • If you smoke, are overweight or have high cholesterol levels.

  • If you have ever had cancer.

  • If you have ever had a depressive illness.

  • If you have ever had yellowing of your skin or the whites of your eyes (jaundice), severe itching, or a skin condition called pemphigoid gestationis during a pregnancy.

  • If you have a rare inherited blood disorder called porphyria.

  • If you are taking any other medicines. This includes any medicines you are taking which are available to buy without a prescription, as well as herbal and complementary medicines.

  • If you have ever had an allergic reaction to a medicine.

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How to take norethisterone

  • Before you start the treatment, read the manufacturer's printed information leaflet from inside the pack. It will give you more information about norethisterone and will provide you with a full list of the side-effects which you may experience from taking it.

  • Take norethisterone exactly as your doctor tells you to. You may be asked to take the tablets regularly each day, or to take them just on certain days of your monthly cycle. This information will be printed on the label of your pack of tablets to remind you, but if you are still unsure, ask your pharmacist for further advice.

  • It is common to take one tablet three times each day, although your dose may be different to this.

  • Swallow the tablets with a drink of water. You can take norethisterone tablets either before or after meals.

  • Try to take your doses at the same times of day, as this will help you to remember to take your doses.

  • If you do forget to take a dose at your usual time, take it as soon as you remember, unless it is nearly time for your next dose in which case leave out the forgotten dose. Remember to take your next dose when it is due but do not take two doses together to make up for a forgotten dose.

Getting the most from your treatment

  • Try to keep your regular appointments with your doctor. This is so your doctor can check on your progress.

  • You should avoid getting pregnant, as norethisterone can affect a developing baby. Use barrier methods of contraception (such as a condom) if you have sex whilst taking norethisterone. If you need further contraceptive advice, speak with your doctor.

  • If you have diabetes you may need to check your blood glucose more frequently, as norethisterone can affect the levels of sugar in your blood. Your doctor will be able to advise you about this.

  • If you are due to have an operation or any medical treatment, tell the person carrying out the treatment that you are taking norethisterone.

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Can norethisterone cause problems?

Along with their useful effects, most medicines can cause unwanted side-effects although not everyone experiences them. The table below contains some of the most common ones associated with norethisterone. You will find a full list in the manufacturer's information leaflet supplied with your medicine. The unwanted effects often improve as your body adjusts to the new medicine, but speak with your doctor or pharmacist if any of the following continue or become troublesome.

Common norethisterone side-effects

What can I do if I experience this?

Shorter periods, no periods, breakthrough bleeding, 'spotting'

Your doctor will discuss this with you before you start treatment

Feeling sick (nausea)

Stick to simple meals - avoid rich and spicy foods. If you are not already doing so, try taking the tablets after a meal


Ask your pharmacist to recommend a suitable painkiller. If the headache is unusually severe or continues, speak with your doctor straightaway

Bloating, fluid retention

If troublesome, speak with your doctor

Less common norethisterone side-effects

What can I do if I experience this?

Feeling dizzy, breast tenderness, changes in weight, feeling tired or difficulty sleeping, feeling depressed, lack of interest in sex, skin reactions

If any of these become troublesome, speak with your doctor

Important: norethisterone can also have some serious side-effects, although these occur only rarely. If you experience any of the following symptoms, stop taking the tablets and contact your doctor for advice straightaway:

  • Any feeling of pain or tightness in your chest.

  • Any disturbances of your vision or hearing.

  • Any unusually severe headaches.

  • Any yellowing of your skin or the whites of your eyes (jaundice).

If you experience any other symptoms which you think may be due to the tablets, speak with your doctor or pharmacist for advice.

How to store norethisterone

  • Keep all medicines out of the reach and sight of children.

  • Store in a cool, dry place, away from direct heat and light.

Important information about all medicines

Important information about all medicines

Never take more than the prescribed dose. If you suspect that you or someone else might have taken an overdose of this medicine, go to the accident and emergency department of your local hospital. Take the container with you, even if it is empty.

This medicine is for you. Never give it to other people even if their condition appears to be the same as yours.

If you buy any medicines 'over the counter', always check with a pharmacist that they are suitable to take with your other medicines.

Do not keep out-of-date or unwanted medicines. Take them to your local pharmacy which will dispose of them for you.

If you have any questions about this medicine ask your pharmacist.

Report side effects to a medicine or vaccine

If you experience side effects, you can report them online through the Yellow Card website.

Further reading and references

Article history

The information on this page is written and peer reviewed by qualified clinicians.

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