Key Takeaways: Using Norethisterone Correctly

Timing is crucial: For period delay, start 3 days before your expected period.
Dosage varies: Different conditions need different doses – always follow your prescription.
Take regularly: If prescribed three times daily, space doses evenly.
Not a contraceptive: Use barrier methods if you need to avoid pregnancy.
Period returns: After stopping, expect a withdrawal bleed within 2-3 days.
Consult a doctor: Before use if you have liver problems, blood clot history, or are pregnant.

Norethisterone is a prescription-only medication. Always follow your doctor's instructions and read the patient information leaflet. This guide summarises the key usage points based on the official PIL and BNF.

Important Medical Advice

If you experience symptoms of a blood clot (sudden shortness of breath, chest pain, leg swelling), severe allergic reaction, or yellowing of the skin, stop taking norethisterone and seek immediate medical help.

How to Take Norethisterone: Step-by-Step Usage Guide

Follow these steps to ensure you take norethisterone correctly and safely.

Check your dose: Verify the number of tablets and times per day as prescribed. The dose depends on why you are taking it (see dosage table below).
Start at the right time: For period delay, begin 3 days before your period is due. For heavy periods, usually start on day 19 of your cycle or as directed.
Swallow tablets whole: Take each 5mg tablet with a glass of water. Do not crush or chew.
Take with or without food: Norethisterone can be taken either way. If you experience nausea, try taking it with a meal.
Space doses evenly: If you need to take it three times a day, aim for every 8 hours (e.g., 8am, 4pm, midnight).
Complete the course: Keep taking for the full number of days prescribed. Do not stop early unless advised.
Missed dose? Take it as soon as you remember, unless it's almost time for the next dose. Never double up.
After finishing: Your period should start within 2-3 days. If it doesn't, check with your doctor – you may need a pregnancy test.

🗒️ Tip: Set an alarm on your phone to help you remember doses, especially if you need to take it three times a day.

Dosage Guide for Different Conditions

The table below shows typical doses as per the patient information leaflet and BNF. Always follow your doctor's prescription.

Condition	Typical Dose	Duration / Notes
Delay a period	One 5mg tablet three times daily (15mg/day)	Start 3 days before expected period; can be taken for up to 10-14 days (max 17 days). Period returns 2-3 days after stopping.
Heavy or painful periods	One 5mg tablet three times daily (15mg/day)	Usually for 10 days, then a withdrawal bleed. May be repeated for next cycles.
Endometriosis	One 5mg tablet three times daily (15mg/day)	Continuous treatment for up to 6 months. If spotting occurs, dose may be increased.
Premenstrual tension (PMT)	One 5mg tablet once daily	Days 16 to 25 of the menstrual cycle.
Breast cancer (palliative)	Up to 40-60mg daily (8-12 tablets)	Specialist use only; dose may be divided.

Important: Doses for children have not been established. Norethisterone is not usually prescribed for children.

Who Should Use Norethisterone?

Norethisterone is suitable for women who need treatment for:

Heavy, painful, or irregular periods.
Endometriosis (to suppress endometrial growth and reduce pain).
Premenstrual tension (PMT) – under specialist guidance.
Delaying a period for a holiday, event, or personal reason.
As part of palliative treatment for breast cancer (under specialist care).

It may also be used for other hormone-related conditions as determined by a doctor. Your GP will assess whether norethisterone is appropriate based on your medical history.

Who Should NOT Use Norethisterone?

Do not take norethisterone if any of the following apply to you (from the PIL):

Allergy to norethisterone or any tablet ingredient.
Pregnancy or suspected pregnancy.
Unexplained vaginal bleeding (not a period).
Current or past blood clot (DVT, pulmonary embolism).
History of heart attack or angina.
Severe liver disease or liver tumour.
Previous pregnancy-related jaundice or severe itching.
Porphyria (a rare inherited blood disorder).
Breast or genital cancer (unless specifically prescribed for breast cancer).

If you have epilepsy, migraine, asthma, kidney disease, or risk factors for clots (obesity, smoking over 35, long-term immobility), discuss with your doctor before use.

To Be Taken With Food or Without Food?

Norethisterone can be taken either with or without food. The tablet is absorbed well regardless of meals. However:

If you experience mild nausea or stomach upset, taking it with food may help.
Avoid grapefruit juice – it may affect the enzyme that metabolises norethisterone (CYP3A4) and alter levels.
Alcohol in moderation is unlikely to interfere, but excessive alcohol may affect liver metabolism.

For consistency, try to take it the same way each day. If you forget and need to take a dose close to a meal, it's fine either way.

Special Conditions: Pregnancy, Breastfeeding & More

Pregnancy

Do not take norethisterone if you are pregnant. Hormonal medicines can affect the developing baby. If you become pregnant while taking it, stop immediately and consult your doctor. Use barrier contraception (condoms) during treatment as norethisterone is not a contraceptive.

Breastfeeding

Norethisterone passes into breast milk in small amounts. It may reduce milk production. Discuss with your doctor whether you should use an alternative feeding method while taking it.

Liver or kidney problems

Norethisterone is contraindicated in severe liver disease. If you have mild to moderate liver or kidney issues, your doctor may still prescribe it but with closer monitoring.

Epilepsy, migraine, asthma, heart disease

These conditions require careful consideration. Norethisterone may worsen migraines or affect fluid balance. Always inform your doctor.

Blood clot risk

If you have personal or family history of clots, or are immobilised after surgery, your doctor may advise against norethisterone or take precautions.

Drug interactions

Tell your doctor about all medicines you take, including antibiotics, epilepsy drugs (phenytoin, carbamazepine), HIV treatments, St John's wort, and some blood pressure medicines. These can reduce norethisterone's effectiveness or increase side effects.

Norethisterone Usage FAQs

What time of day should I take norethisterone?

Take it at the same times each day. If you're on three times daily, space doses evenly (e.g., 8am, 4pm, midnight). This keeps hormone levels steady and reduces breakthrough bleeding.

Can I stop norethisterone early if I get side effects?

If side effects are bothersome, contact your doctor before stopping. Stopping suddenly may cause heavy bleeding. Your doctor can advise whether to continue or switch treatment.

What should I do if I miss a dose?

Take it as soon as you remember, unless it's almost time for your next dose. Skip the missed dose and continue as normal. Do not take two doses together.

Will norethisterone affect my fertility later?

No, norethisterone does not have a permanent effect on fertility. Your menstrual cycle and ovulation should return to normal once you stop taking it. If you have concerns, speak with your GP.

Can I take norethisterone with paracetamol or ibuprofen?

Yes, occasional use of paracetamol or ibuprofen is generally safe with norethisterone. However, long-term use of NSAIDs like ibuprofen may increase bleeding risk – check with your doctor.