Norethisterone Tablets

“Period delay” means postponing a scheduled menstrual bleed for a short time – for example:

– A holiday or honeymoon

– A religious festival or pilgrimage

– Sports competitions, exams, or other events

Once you stop the tablets, your hormone levels fall and your period starts a few days later, then your cycle should settle back to normal.

Norethisterone is a progestogen. In a normal cycle, when progesterone levels fall, the womb lining is shed as a period. By taking norethisterone:

– Progesterone-type hormone levels stay artificially high

– The lining stays thick and stable

– A period is held off until you stop the tablets

When you stop, hormone levels drop and the lining is shed, triggering a period.

That depends on how long you keep taking the tablets:

– You can usually delay your period for up to around 2–3 weeks with norethisterone, under prescriber guidance.

Your prescriber will specify the maximum number of days that is appropriate for you.

Most women find that their period:

– Starts 2–3 days after stopping norethisterone

– Then the next cycle continues as normal

If your period has not started within about a week after stopping, you should do a pregnancy test and contact a clinician.

No. This is really important:

– Norethisterone for period delay is not a contraceptive

– It does not protect against pregnancy, even if you don’t have a bleed while taking it

You still need to:

– Use your usual contraceptive method correctly, and/or

– Use condoms to reduce the risk of pregnancy and STIs.

You should not use norethisterone for period delay without medical advice if you:

– Have ever had a blood clot in your leg or lungs (DVT/PE)

– Have a close relative who had a serious clot at a young age

– Have had a heart attack, stroke, or certain heart/vascular diseases

– Have severe liver problems, liver tumours, or unexplained jaundice

– Have unexplained vaginal bleeding that your doctor has not investigated

– Have, or have had, breast cancer or certain hormone-sensitive cancers, unless a specialist says it is appropriate

– Are pregnant, might be pregnant, or are trying to conceive

Your clinician will go through a clot-risk and medical history checklist before prescribing.

Most women tolerate norethisterone well, especially when used short term, but side effects can occur.

Common or less serious side effects can include:

– Bloating or abdominal discomfort

– Nausea (feeling sick)

– Headache or dizziness

– Breast tenderness

– Changes in mood or sex drive

– Breakthrough spotting or irregular bleeding

These are usually mild and settle once the tablets are stopped. If they are severe, persistent or worrying, contact a doctor or pharmacist.

Rare but more serious side effects include:

– Blood clots (venous thromboembolism)

Seek urgent medical help if you develop symptoms such as:

– Sudden shortness of breath, chest pain, coughing up blood

– Pain, swelling, redness or warmth in one leg

– Sudden severe headache, vision changes, difficulty speaking, weakness on one side

Stop taking norethisterone and get advice immediately if you develop:

– Severe chest pain or breathlessness

– Severe headaches or migraines that are new or much worse

– Yellowing of the skin or eyes (jaundice)

– Severe allergic reaction (swelling of face/lips/tongue, difficulty breathing, widespread rash)

It depends on which pill you use and why you are delaying your period:

Combined contraceptive pill:

– Often, the simplest and safer option to avoid a bleed is to run packs together or shorten the hormone-free interval, rather than using norethisterone.

– Your prescriber may suggest adjusting your pill regimen instead of, or as well as, norethisterone.

Progestogen-only methods (mini-pill, implant, injection, IUS/IUD):

– These can cause unpredictable bleeding, and norethisterone may not guarantee complete suppression of bleeding.

Always follow the plan given by your prescriber – do not alter your contraceptive routine without checking first.

Norethisterone for period delay is intended for occasional use, not as a monthly long-term solution.

– Repeated courses may increase exposure to clot risk and side effects.

– If you need frequent control of your cycle, your clinician may discuss alternative options, such as combined hormonal contraception, certain IUS devices, or other hormonal regimes.

Pregnancy:

– You must not take norethisterone if you are pregnant or think you might be pregnant. If your period does not come within a week after stopping the tablets, do a pregnancy test and seek advice.

Breastfeeding:

– Norethisterone is usually avoided or used cautiously in breastfeeding, depending on timing and alternatives. Your prescriber will advise whether it’s appropriate for you or suggest another option.

Always tell your clinician if you could be pregnant, are pregnant, or are breastfeeding before starting treatment.

Some women experience light spotting or breakthrough bleeding even while on norethisterone – especially if it was started late or if cycles are irregular.

If this happens:

– It does not usually mean anything serious

– Continue the tablets as prescribed if the spotting is light and you feel well

Contact a clinician if:

– Bleeding is heavy, painful or persistent

– You have bleeding after sex or between cycles that you find worrying

– You are unsure whether to continue the course

If you forget a dose:

– Take it as soon as you remember, then continue as normal

– Do not take a double dose to make up for a missed tablet

Missing tablets may make it more likely that you get spotting or bleeding, and possibly reduce the effectiveness of the period delay.

Seek urgent medical advice (GP, NHS 111, or A&E/999) if:

– You develop sudden chest pain, shortness of breath, or coughing up blood

– One leg becomes painful, swollen, red or warm

– You have a sudden severe headache, vision changes, difficulty speaking, or weakness on one side of the body

– You notice yellowing of the skin or eyes, severe abdominal pain, or very dark urine

– You have signs of a severe allergic reaction (swelling of face/lips/tongue, difficulty breathing, widespread rash)

Stop taking norethisterone and seek immediate help if any of these happen.

There is no specific interaction between norethisterone and alcohol listed in major references.

However:

– It’s sensible to keep alcohol moderate, especially if you are travelling, flying, or otherwise at increased clot risk.

– Heavy drinking can worsen nausea, headaches and general wellbeing, which may overlap with side effects of the tablets.