Norethisterone is a synthetic form of the hormone progesterone that is often used to delay periods.
You may be considering taking norethisterone if you experience painful, heavy or irregular periods. Norethisterone is a synthetic form of the hormone progesterone, which is used in contraceptive pills, menopausal hormone therapy, and for the treatment of gynaecological disorders.
Everything you need to know about norethisterone, including how it works and potential side-effects.
What is norethisterone?
Norethisterone 5mg tablets can also be prescribed to delay your period, for instance if you don’t want it to come while you’re on holiday or if you’re taking part in a sporting event.
Can you buy norethisterone?
Norethisterone is available on prescription from your doctor, but if you want to take it to delay your period it is now available on the high street as a walk-in service at Superdrug pharmacies.
They will ask you to fill out a brief questionnaire and one of their doctors will review your order and prescribe a suitable treatment.
Several pharmacies also offer on-line prescribing of norethisterone.
How does norethisterone work?
Norethisterone is a man-made version of the female sex hormone progesterone. It works by mimicking the effects of your natural progesterone.
Your progesterone levels naturally fluctuate throughout your monthly menstrual cycle. As progesterone levels increase your womb lining flourishes, ready to receive a fertilised egg. If you don’t get pregnant the levels fall again, causing your womb lining to be shed as a period. If you do get pregnant your progesterone levels remain high to help maintain a healthy womb lining for the ongoing pregnancy.
Can norethisterone stop your period?
Taking norethisterone at various points throughout this cycle can manipulate or regulate the growth and shedding of the womb lining. For instance, taking norethisterone a few days before your period is due will trick your body into thinking you’re pregnant, so you don’t have a period until you stop taking the norethisterone.
Taking norethisterone a few days before your period is due will trick your body into thinking you’re pregnant.
If you have endometriosis, taking norethisterone every day has the same effect and stops the abnormal tissue from going through monthly changes. Your periods are likely to stop during treatment and after you stop taking norethisterone the patches of endometrial tissue may have shrunk.
Key facts about norethisterone
- Norethisterone is known as norethindrone in the US.
- Primolut N and Utovlan are brand names for norethisterone 5mg tablets.
- Your doctor may ask you to take norethisterone every day or for just a few days each month, depending on what you’re taking it for.
- Norethisterone 5mg tablets are not a contraceptive.
- Don’t take norethisterone if you are pregnant.
- Use a non-hormonal method of contraceptionsuch as condoms to prevent pregnancy while taking norethisterone.
- The most common side effects are headaches, feeling sick and changes to your period, such as spotting between periods.
- It’s fine to drink alcohol while you’re taking norethisterone.
Who shouldn’t take norethisterone?
You should not take norethisterone 5mg tablets if you experience any of the following:
- If you are pregnant or think you could be.
- If you are breastfeeding.
- If you have abnormal vaginal bleeding that hasn’t been investigated by your doctor.
- If you have a history of genital cancer or breast cancer(unless you have been prescribed norethisterone to treat breast cancer).
- If you have recently had angina, a heart attackor a stroke caused by a blood clot.
- Have a blood clot in the leg or lungs (thromboembolism, eg deep vein thrombosisor pulmonary embolism).
- If you have liver problems or a history of liver cancer.
- If you have ever had jaundice, severe itching or a blistering skin rash called pemphigoid gestationis during pregnancy.
- If you have a rare metabolic disorder called porphyria.
Some people may need extra monitoring while taking norethisterone. Make sure your doctor knows if you have any of the following:
- Kidney problems
- Heart failure
- High blood pressure
- A long-term condition called systemic lupus erythematosus (SLE)
- A history of or increased risk of blood clots such as deep vein thrombosisor pulmonary embolism, for example because you smoke, are overweight or have high cholesterol levels
- A history of depression
How do I take norethisterone?
You take norethisterone either on selected days during your menstrual cycle or continuously, depending on the reason you’re taking it. Always follow your doctor’s instructions. You can take the tablets either with or without food.
Norethisterone to delay your period
Start taking norethisterone three days before your period is due. Take one 5mg tablet three times a day, for up to 14 days. You should get your period two to three days after you stop taking the tablets.
Norethisterone to treat heavy periods
If you’re having continuous, heavy bleeding your doctor may ask you to take one 5mg tablet three times a day for 10 days to stop the bleeding. Your bleeding should stop within the first three days but keep taking the tablets for the full 10 days. If your bleeding doesn’t stop you should see your doctor. Two to four days after you stop taking the tablets you should have a period.
For heavy periods (menorrhagia) your doctor may recommend you take norethisterone for a number of days each month. For example, 5mg three times a day from day 5 to 26. (Day one is the first day of your period.) Your doctor may ask you to do this for three to six months.
Norethisterone to treat painful periods
Take one 5mg tablet three times a day on days 5 to 24 of your monthly cycle. (Day one is the first day of your period.) Your doctor will usually ask you to do this for three or four months.
Norethisterone to treat endometriosis
You’ll usually be asked to take two 5mg tablets twice a day, every day, for four to six months, starting on day five of your cycle. Your bleeding will usually stop during the treatment; if you get any spotting your doctor may increase your dose.
Norethisterone to treat cancer
High doses of norethisterone are sometimes used to treat breast cancer. Follow your doctor’s instructions.
What if you miss a dose of norethisterone?
If you forget to take a norethisterone dose take it as soon as you remember, unless it’s nearly time for your next dose. In this case just leave out the missed dose and take your next dose as usual when it is due. Don’t take a double dose to make up for a missed dose
Medicines and their possible side-effects can affect people in different ways. The following are some of the side effects that may be associated with norethisterone 5mg tablets. Just because a side effect is stated here doesn’t mean that all people taking norethisterone will experience that or any side effect.
Common norethisterone side-effects
Common side-effects that impact between 1 in 10 and 1 in 100 women include:
- Change in your period, including breakthrough bleeding or spotting, or stopping of periods.
- Feeling sick.
Other possible norethisterone side-effects
- Breast discomfort or tenderness.
- Fluid retention causing swelling (oedema).
- Skin reactions such as acne, rash or itching.
- Inability to sleep (insomnia)
- Increased blood pressure.
- Change in sex drive.
- Weight gain.
- Hair loss (alopecia).
- Excessive hair growth (hirsutism).
When should you be concerned?
Stop taking norethisterone and see a doctor straight away if you get severe headaches or migraine; stabbing pains or swelling in one leg; pain on breathing or coughing; coughing up blood; breathlessness; sudden chest pain; sudden numbness affecting one side or part of the body; sudden changes in your vision or hearing; or yellowing of your skin or whites of your eyes (jaundice).
Read the leaflet that comes with your medicine or talk to your doctor or pharmacist if you want more information about the possible side effects of norethisterone 5mg tablets. If you think you have experienced a side effect, did you know you can report this using the yellow card website?
Can I take norethisterone with other medicines?
It’s important to tell your doctor or pharmacist if you’re already taking any medicines, including those bought without a prescription and herbal medicines, before you start taking norethisterone. It is fine to painkillers such as paracetamol, ibuprofen and aspirin with norethisterone.