Femastin 1mg Tab

Overview

Femastin 1 mg Tablet contains Estriol, the weakest of the three naturally occurring human oestrogens (oestrone, oestradiol, estriol), manufactured by Square Pharmaceuticals PLC. Estriol has preferential affinity for the uterine cervix, vagina, and lower urinary tract over the endometrium. It is used for the management of menopausal symptoms including urogenital atrophy (vaginal dryness, dyspareunia), recurrent urinary tract infections in post-menopausal women, urinary urgency and stress incontinence, and as part of hormone replacement therapy.

Dosage and Administration

Adults: 1–4 mg daily under physician supervision, often cyclically or at the lowest effective dose. For urogenital symptoms, typically 1 mg daily for 2–3 weeks, then reduced to maintenance.

Interaction

Induction of hepatic enzymes (rifampicin, carbamazepine, phenytoin) may reduce estriol efficacy. Concurrent use with other oestrogens or progestogens should be carefully managed. May reduce anticoagulant effect of warfarin.

Contraindications

Contraindicated in oestrogen-sensitive cancers (breast, endometrial), undiagnosed abnormal genital bleeding, active thromboembolism, liver disease, porphyria, and known hypersensitivity.

Side Effects

Breast tenderness, fluid retention, headache, nausea, and bloating. Risk of endometrial hyperplasia with unopposed oestrogen (less risk with estriol than oestradiol due to weaker endometrial activity).

Pregnancy and Lactation

Contraindicated during pregnancy. Not for use during breastfeeding — may suppress lactation.

Precautions and Warnings

Regular gynaecological review including breast examination and (in women with intact uterus) endometrial surveillance. Lowest effective dose for the shortest necessary duration. Do not use without specialist assessment if personal or family history of breast or uterine cancer.

Storage Conditions

Store below 25°C in a cool, dry place. Keep out of the reach of children.

Frequently Asked Questions

Why is estriol preferred over oestradiol for vaginal/urogenital symptoms?
Estriol has a weaker effect on the endometrium and breast tissue compared to oestradiol, reducing the risk of endometrial hyperplasia when used vaginally or at low oral doses; it preferentially targets the vagina, cervix, and lower urinary tract, making it well-suited for urogenital symptoms.

Does estriol need to be combined with a progestogen?
At low doses used specifically for urogenital symptoms (vaginal route), estriol typically does not require progestogen co-prescription as its endometrial stimulation is minimal; at higher systemic doses, the prescribing physician will assess whether progestogen protection is needed.

This content is for informational purposes only and does not substitute professional medical advice. Please consult a registered physician before taking any medication.