Norethindrone is a female hormone treatment.
You may be asked to take the tablets regularly each day, or to take them just on certain days of the month.
The most common side-effects are feeling bloated, nausea and headache. These are generally mild in nature.
What is norethindrone?
|Type of medicine||Progestin (female hormone)|
|Used for||Endometriosis, painful or heavy menstrual periods|
Norethindrone (also known as norethisterone) is a man-made form of progesterone, a naturally occurring female sex hormone. It is referred to as a progestin 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 Aygestin® are used to treat heavy and painful menstrual periods particularly if they are associated with a condition called endometriosis. Aygestin® tablets are also used to treat endometriosis itself. Higher doses are used in the treatment of some female cancers, such as breast cancer.
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. Norethindrone can also be considered for heavy periods not associated with endometriosis.
This leaflet discusses norethindrone when it is used to treat endometriosis or painful or heavy periods. There are a number of other medicine leaflets which will give you more information about norethindrone if you are taking it for birth control or as HRT. These are: Progestin-only contraceptive tablets, Combination oral contraceptives and Estrogen and progestin for HRT.
What to know before taking norethindrone
Some medicines are not suitable for people with certain conditions, and sometimes a medicine may only be used if extra care is taken. For these reasons, before you start taking norethindrone it is important that your physician 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, migraine, 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.
How to take norethindrone tablets
- Before you start this treatment, read the manufacturer's printed information leaflet from inside your pack. The manufacturer's leaflet will give you more information about norethindrone and a full list of side-effects which you may experience from taking it.
- Take norethindrone exactly as your physician 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.
- For treatment of endometriosis it is usual to start with a low dose of half to one tablet (2.5 mg-5 mg) each day. Your physician will ask you to increase your dose slightly every two weeks until you are taking three tablets (15 mg) each day.
- If you are taking norethindrone for painful or heavy menstrual periods, the usual dose is between half and two tablets each day (2.5 mg-10 mg) for five to ten days in each menstrual cycle.
- Swallow the tablets with a drink of water. You can take norethindrone 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 them.
- 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 all your regular appointments with your physician. This is so your physician can check on your progress.
- You should avoid getting pregnant as norethindrone can affect a developing baby. Use barrier methods of birth control (such as a condom) if you have sex whilst taking norethindrone. If you need further birth control (contraception) advice, speak with your physician.
- If you have diabetes you may need to check your blood sugar (glucose) more frequently, as norethindrone can affect the levels of sugar in your blood. Your physician will be able to advise you about this.
- If you are due to have surgery or any medical treatment, tell the person carrying out the treatment that you are taking norethindrone.
Norethindrone side effects and 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 norethindrone. 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 physician or pharmacist if any of the following continue or become troublesome.
|Common norethindrone side-effects||What can I do if I experience this?|
|Shorter menstrual periods, no periods, breakthrough bleeding, 'spotting'||Your physician will discuss this with you before you start treatment|
|Nausea||Stick to simple meals - avoid rich and spicy foods. If you are not already doing so, try taking the tablets after a meal|
|Headache||Ask your pharmacist to recommend a suitable painkiller. If the headache is unusually severe or continues, speak with your physician straightaway|
|Bloating, fluid retention||If troublesome, speak with your physician|
|Less common norethindrone 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 physician|
Important: norethindrone 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 physician 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 this medicine, speak with your physician or pharmacist.
How to store norethindrone tablets
- 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
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 Emergency Room 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. Ask your pharmacist about ways to dispose of medicines safely in your local area.
If you have any questions about this medicine ask your pharmacist.
Further reading and references
FDA Drug Label, Aygestin® 5 mg tablets - norethindrone acetate; Teva Women's Health Inc, DailyMed, National Institutes of Health, US National Library of Medicine. Dated August 2019.
FDA Drug Label, Norethindrone acetate 5 mg tablets; Amneal Pharmaceuticals of New York LLC, DailyMed, National Institutes of Health, US National Library of Medicine. Dated December 2022.