Lynestrenol

What it is and how it works

Lynestrenol is a prodrug that is converted in the liver to norethisterone, a progestogen with weak androgenic activity. It transforms proliferative endometrium to secretory endometrium, suppresses gonadotrophin release and ovulation at higher doses, and thickens cervical mucus.

Indications

Progestogen-only oral contraception (low dose); menstrual disorders such as dysfunctional uterine bleeding, menorrhagia and secondary amenorrhoea; endometriosis.

Dosage and administration (summary)

Contraception: 0.5 mg orally daily without interruption. Gynaecological disorders: typically 5–10 mg daily, with regimen and duration depending on the indication.

Contraindications

Known or suspected pregnancy; active venous thromboembolism; severe or recent hepatic disease or liver tumours; undiagnosed vaginal bleeding; known or suspected progestogen-sensitive malignancy.

Warnings and precautions

Irregular bleeding is common, particularly with progestogen-only contraception. May impair glucose tolerance and adversely affect lipids, and may cause androgenic effects (acne, hirsutism) at higher doses. Use with caution in patients with a history of thromboembolism, depression, hypertension or diabetes.

Pregnancy

Contraindicated in pregnancy.

Storage and supply

Store below 25–30 °C, protected from light and moisture.

Source: reference summary prepared from the EU SmPC/EPAR, BNF and WHO Model Formulary. The approved product information in Iran governs.