norethisterone at a glance
Medicine class
Synthetic progestogen
Main roles
Menstrual bleeding disorders, painful periods, endometriosis, premenstrual symptoms and postponing menstruation
Contraception
Norethisterone prescribed to postpone a period is not a contraceptive
Administration
Oral tablets; Primolut N tablets should be swallowed whole with liquid
What is norethisterone used for?
Selected products are licensed for several menstrual and gynaecological conditions. Their licences are not identical.
Dysfunctional or heavy uterine bleeding and frequent or irregular menstruation
Painful periods
Premenstrual syndrome
Endometriosis
Postponement of menstruation
Specialist treatment of disseminated breast carcinoma with Utovlan; this does not apply to Primolut N
How does norethisterone work?
Norethisterone activates progesterone-like pathways. It changes the endometrium and suppresses pituitary signals involved in ovulation, helping control the timing and pattern of uterine bleeding. It also has weak androgenic and oestrogenic activity, and some is converted to ethinylestradiol after oral administration.
norethisterone preparations and strengths
Tablet
Route: Oral
Strengths: 5 mg
How to take norethisterone
Take norethisterone exactly as shown on the dispensing label because use varies by condition and product. Swallow Primolut N tablets whole with liquid. Do not change or stop the prescribed schedule without advice. Treatment used to postpone menstruation does not provide contraception.
Check the product label and leaflet because Utovlan and Primolut N do not have identical licences or cautions.
Tell the prescriber if bleeding persists, becomes heavy again or occurs unexpectedly.
Both selected products contain lactose.
norethisterone side effects
Common or expected effects
- Headache
- Nausea
- Fluid retention or swelling
- Changes in vaginal bleeding, including spotting, lighter bleeding or absent periods
- Breast tenderness
- Dizziness
Get urgent medical advice
- Symptoms of a blood clot, heart attack or stroke
- Severe allergic reaction or angioedema
- Jaundice or deterioration in liver function
- New migraine-type headache or sudden visual disturbance
- Severe or worsening depression
norethisterone in pregnancy
Norethisterone is contraindicated during pregnancy. Pregnancy should be excluded before treatment and before further treatment if expected bleeding does not occur. Norethisterone used for menstrual postponement is not contraceptive.
norethisterone while breastfeeding
Do not start norethisterone while breastfeeding without product-specific prescriber advice. Primolut N is contraindicated during lactation because norethisterone can pass into breast milk.
norethisterone interactions
Check prescribed, over-the-counter and herbal products before treatment. Important interactions include:
Enzyme-inducing antiseizure medicines, including carbamazepine, phenytoin, primidone and barbiturates
They can increase norethisterone clearance, causing altered bleeding or reduced therapeutic effect.
Rifampicin or rifabutin
These enzyme inducers can lower norethisterone exposure and reduce its effect.
Common questions about norethisterone
Answers are fully visible for fast scanning and source review.
Is norethisterone a contraceptive?
Not when prescribed for menstrual disorders or period postponement.
Can norethisterone delay a period?
Yes. It is licensed to postpone menstruation, although effectiveness and when bleeding returns vary between individuals.
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.