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Synthetic Progestogen Pregnancy: Contraindicated in pregnancy (§4.6, verbatim: 'Contraindicated in pregnancy.'; also listed in §4.3). The bundle's §4.6 gives no lactation or fertility statement.

Norethisterone

Brand names: Primolut N, Utovlan

Norethisterone is an orally active progestogen used for menstrual disorders such as heavy or painful periods, to delay menstruation, in endometriosis, and as a component of some hormonal contraceptives and hormone replacement therapy.

Adult dose

Dose: LOW DOSE — Dysfunctional uterine bleeding, polymenorrhoea, menorrhagia, dysmenorrhoea and metropathia haemorrhagica: 1 tablet three times daily for 10 days; bleeding usually stops within 48 hours, and withdrawal bleeding resembling true menstruation occurs a few days after the end of treatment. To prevent recurrence, 1 tablet twice daily from days 19 to 26 of the two subsequent cycles. Endometriosis: 1 tablet three times daily for a minimum treatment period of six months; the dosage should be increased to 4 or 5 tablets a day if spotting occurs, and the initial dosage resumed when bleeding or spotting stops. Postponement of menstruation: 1 tablet three times daily, starting three days before the expected onset of menstruation — menstruation usually follows within three days of finishing the treatment. Pre-menstrual syndrome: 1 tablet daily from days 16 to 25 of the menstrual cycle. HIGH DOSE, a different indication quoted only so it is not confused with the above — disseminated breast carcinoma: starting dose 8 tablets (40 mg) per day, increasing to 12 tablets (60 mg) if no regression is noted. TABLET STRENGTH CAVEAT: the §4.2 text in this bundle expresses the low-dose regimens as a number of TABLETS and does not itself state the tablet strength, so no milligram figure has been asserted for them — confirm the strength of the Utovlan tablet being prescribed before converting.
Route: Oral. §4.2 Method of administration: 'Oral Administration'.
Frequency: Three times daily for 10 days in the dysfunctional uterine bleeding group, then twice daily on days 19-26 of the two subsequent cycles; three times daily for at least six months in endometriosis; three times daily from three days before the expected period for postponement of menstruation; once daily on days 16-25 for pre-menstrual syndrome.
NO MAXIMUM DOSE IS RECORDED, DELIBERATELY. The only ceiling-like figures in §4.2 — 8 tablets (40 mg) and 12 tablets (60 mg) per day — belong to the HIGH-DOSE disseminated breast carcinoma indication, which is a different indication from this page's primary one; importing them as a maxDose for menstrual-disorder dosing would be wrong. The label states no ceiling for the low-dose gynaecological regimens; the nearest thing is endometriosis, where the dose may be INCREASED to 4 or 5 tablets a day if spotting occurs. || §4.4: if menstrual bleeding fails to follow a course of Utovlan, the possibility of pregnancy must be excluded before a further course is given. || §4.4 ends at the source-fetch truncation marker (mid-sentence on hepatic adenoma), so the warnings list is PARTIAL. || PAEDIATRIC: §4.2 contains no paediatric population section and no paediatric posology, so paedDose is null and nothing has been scaled from the adult regimens.

Dose independently re-sourced from UK Summary of Product Characteristics (SPC) via the eMC — clinician-reviewed. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

  • Hypersensitivity to the active substance or any of the excipients listed in section 6.1
  • Pregnancy
  • Previous idiopathic or current venous thromboembolism (deep vein thrombosis, pulmonary embolism)
  • Active or recent arterial thromboembolic disease (e.g. angina, myocardial infarction)
  • Disturbance of liver function
  • History during pregnancy of idiopathic jaundice
  • Severe pruritus or pemphigoid gestationis
  • Undiagnosed irregular vaginal bleeding
  • Porphyria
  • Effectively contraindicated per §4.4 until assessed: use of progestogens in patients with a personal or strong family history of thromboembolism or recurrent spontaneous abortion should be viewed as contraindicated until a thorough evaluation of thrombophilic factors has been made or anticoagulant treatment initiated
  • PROVENANCE: §4.3 of the Utovlan Tablets SPC, complete in the bundle, plus the conditional exclusion in §4.4.

Side effects

  • Genitourinary: breakthrough bleeding, spotting, amenorrhoea, abnormal uterine bleeding (irregular, increased or decreased), alterations of cervical secretions, cervical erosions, prolonged anovulation
  • Reproductive system and breast: galactorrhoea, mastodynia, tenderness
  • Central nervous system: depression, headache, dizziness, fatigue, insomnia, nervousness, somnolence, confusion, euphoria, loss of concentration, vision disorders
  • Gastrointestinal / hepatobiliary: nausea, vomiting, cholestatic icterus or jaundice, constipation, diarrhoea, dry mouth, disturbed liver function
  • Neoplasms: hepatic adenoma
  • Metabolic and nutritional: altered serum lipid and lipoprotein profiles, increased fasting glucose, increased fasting insulin, decreased glucose tolerance, adrenergic-like effects (fine hand tremors, sweating, cramps in the calves at night), corticoid-like effects (Cushingoid syndrome), diabetic cataract, exacerbation of diabetes mellitus, glycosuria
  • Cardiovascular: thrombo-embolic disorders, cerebral and myocardial infarction, congestive heart failure, increased blood pressure, palpitations, pulmonary embolism, retinal thrombosis, tachycardia, thrombophlebitis
  • Skin and mucous membranes: acne, hirsutism, alopecia, pruritus, rash, urticaria
  • Allergy: hypersensitivity reactions including anaphylaxis, anaphylactoid reactions and angioedema
  • Miscellaneous: oedema / fluid retention, bloating, weight gain, pyrexia, change in appetite, change in libido, hypercalcaemia, malaise
  • PROVENANCE AND FREQUENCY CAVEAT: §4.8 of the Utovlan Tablets SPC, complete in the bundle. The label groups these by body system and assigns NO frequency bands — it introduces them as effects associated with progestogens given alone at low doses — so no frequency is asserted here.

Monitoring

  • Exclude pregnancy before giving a further course if menstrual bleeding fails to follow a course of treatment
  • DISCONTINUE therapy if any of the following occur: jaundice or deterioration in liver function; a significant increase in blood pressure; new onset of migraine-type headache
  • Assess status and need for treatment carefully in any patient who develops symptoms suggestive of thromboembolic complications, and withdraw the drug if venous thromboembolism develops after starting therapy
  • Advise patients to contact their doctor immediately if they become aware of a potential thromboembolic symptom (painful swelling in the leg, sudden pain in the chest, dyspnoea)
  • Evaluate ophthalmologically any patient who develops acute impairment of vision, proptosis, diplopia or migraine headache, to exclude papilloedema or retinal vascular lesions, before continuing medication
  • Take special care in conditions that may be aggravated by fluid retention: epilepsy, migraine, asthma, cardiac dysfunction, renal dysfunction
  • Consider stopping progestogen therapy 4-6 weeks pre-operatively where prolonged immobilisation is likely to follow elective surgery, particularly abdominal or lower-limb orthopaedic surgery, and do not restart until the patient is fully remobilised
  • Weigh risks and benefits carefully where the patient is already taking anticoagulants
  • This list may be incomplete — check the full SPC.

Clinical monograph

How it works

It is a synthetic progestogen that acts on progesterone receptors to oppose oestrogenic effects on the endometrium and modulate the menstrual cycle.

Prescribing in practice

  • It is associated with an increased risk of venous thromboembolism, so assess thrombotic risk factors before prescribing, particularly at higher doses.
  • At higher therapeutic doses it can be partially metabolised to ethinylestradiol, which is relevant to thrombotic risk assessment.
  • It is not a reliable contraceptive at the doses used for menstrual disorders unless prescribed specifically as a contraceptive.

Monitoring

Review blood pressure, bleeding pattern and thrombotic risk factors, and reassess the need for continued treatment periodically.

Counselling the patient

  • Report symptoms of a blood clot such as leg pain or swelling, chest pain or breathlessness urgently.
  • When used for menstrual disorders this is not a contraceptive unless specifically prescribed as one.
  • Take regularly as directed for your indication and report any unusual bleeding.

Evidence & guidelines

Norethisterone is a long-established progestogen, and prescribing guidance highlights venous thromboembolism risk, especially at higher doses.

Reference: NICE NG88 (Heavy Menstrual Bleeding); FSRH Guideline; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

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