NORMENS 5 MG TABLET
NORTHISTERONE ACETATE BP
What it does
Northisterone is a medication that helps manage certain hormonal conditions.
Commonly used for: irregular periods (oligomenorrhea), absence of menstrual periods (amenorrhea), endometriosis, contraception
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Source: Pharmacy and Poisons Board · fetched 2026-01-28 22:03:23 · updated 2026-03-23 04:48:31
About this medicine
Northisterone is a medication that helps manage certain hormonal conditions.
What it treats
- irregular periods (oligomenorrhea)
- absence of menstrual periods (amenorrhea)
- endometriosis
- contraception
How it works
Northisterone works by mimicking the effects of natural hormones in the body, helping to regulate menstrual cycles and manage hormonal imbalances.
Who it's for
Northisterone is for people who need help with their menstrual cycle or have specific hormonal issues.
AI-assisted summary grounded in BNF data - general information only, not medical advice. Always confirm with your pharmacist or doctor.
Clinical monograph: northisterone
Norethisterone is a synthetic progestogen, a form of the hormone progesterone. It is primarily used in various therapeutic applications including contraception, management of menstrual disorders, and treatment of endometriosis. Norethisterone works by mimicking the effects of natural progesterone in the body, exerting effects on the endometrium and other reproductive tissues.
Indications
- Contraception (as part of combined oral contraceptives or as a progestogen-only pill)
- Management of irregular menstrual cycles
- Treatment of endometriosis
- Management of premenstrual syndrome (PMS)
- Hormone replacement therapy in menopausal women
Dosage
Children: Refer to BNF for Children for specific dosages and guidance.
Adults: Refer to BNF for specific dosages as it varies based on indication.
Mechanism of action
Norethisterone binds to progesterone receptors in target tissues, leading to alterations in gene expression that result in changes in the endometrial lining, cervical mucus, and myometrial contractions. This action helps to prevent ovulation, alter menstrual flow, and provide relief from symptoms associated with endometriosis.
Pharmacodynamics
Norethisterone exhibits progestational activity, which includes promoting secretory changes in the endometrium, thickening of cervical mucus, and inhibiting uterine contractions. It also has some androgenic effects, which may contribute to side effects such as acne or weight gain in some patients.
Pharmacokinetics
Norethisterone is well absorbed after oral administration, with peak plasma concentrations typically occurring within 1 to 5 hours. It is extensively metabolized in the liver, primarily via the cytochrome P450 system. The elimination half-life is approximately 8 to 12 hours. Norethisterone is excreted mainly in urine as metabolites, and a small amount is excreted in feces.
Contra-indications
- Known or suspected pregnancy
- Active thromboembolic disorders
- Severe hepatic impairment
- History of hormone-sensitive cancers
- Unexplained vaginal bleeding
- Porphyria
Adverse effects
- Nausea
- Weight gain
- Headache
- Menstrual irregularities
- Mood changes
- Breast tenderness
- Fluid retention
- Acne
- Changes in libido
Interactions
- Anticonvulsants (e.g., phenytoin, carbamazepine) may reduce efficacy
- Rifampicin may reduce efficacy
- St. John's Wort may reduce efficacy
- CYP3A4 inducers may alter metabolism and reduce effectiveness
- CYP3A4 inhibitors may increase serum levels and risk of side effects
Precautions
- Monitor for signs of thromboembolism
- Caution in patients with hypertension or diabetes
- Assess liver function prior to use
- Monitor for changes in mood or depressive symptoms
- Regular gynecological assessments are recommended
Pregnancy
Northisterone is contraindicated in pregnancy due to potential harm to the fetus.
Breast-feeding
Northisterone is excreted in breast milk; caution is advised when administering to nursing mothers.
Storage
Store in a cool, dry place away from direct sunlight. Keep out of reach of children.
Formulations
- Tablets
- Oral suspension
AI-synthesized from BNF references - general information only, not a substitute for professional medical advice or the current BNF. Verify doses with a pharmacist.