Topical oestrogen (low-potency) Pregnancy: §4.6: not indicated during pregnancy. If pregnancy occurs during treatment, withdraw immediately. Most epidemiological studies relevant to inadvertent foetal exposure to oestrogens indicate no teratogenic or foetotoxic effects. Not indicated during lactation — estriol is excreted in breast milk and may decrease milk production. Intended for postmenopausal (naturally and surgically induced) women only.

Estriol

Brand names: Ovestin, Blissel

A short-acting natural oestrogen used mainly as topical (vaginal) therapy for urogenital atrophy and related menopausal symptoms.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: Atrophic vaginitis — 1 pessary (0.5 mg estriol) per day for the first weeks, then a gradual reduction based on relief of symptoms until a maintenance dose (e.g. 1 pessary twice a week) is reached

Route: Intravaginal — insert the pessary before retiring at night

Frequency: Once daily initially, then reduced to a maintenance frequency (e.g. twice weekly)

Max: Daily dosing for a maximum of 4 weeks before reducing to maintenance; two doses should never be administered on the same day

SOURCE PRODUCT: Estriol 0.5 mg pessary — an oestrogen-only product for intravaginal use, for adults and the elderly. OTHER INDICATIONS: pre-surgery therapy in postmenopausal women undergoing vaginal surgery — 1 pessary per day in the 2 weeks before surgery; post-surgery therapy — allow a period of at least 2 weeks after surgery before resuming therapy, using 1 pessary twice a week. MISSED DOSE: administer as soon as remembered unless it is more than 12 hours overdue, in which case skip it and administer the next dose at the normal time. For initiation and continuation of treatment of postmenopausal symptoms the lowest effective dose for the shortest duration should be used. Because systemic exposure of estriol remains closely to the normal postmenopausal range when used twice weekly, it is not recommended to add a progestagen (see §4.4). STARTING: in women not taking HRT, or women switching from a continuous combined HRT product, treatment may be started on any day; women switching from a cyclic HRT regimen should start one week after completion of the cycle. Vaginal infections should be treated before starting therapy. Intended for treatment in postmenopausal (naturally and surgically induced) women only. NOTE ON US SOURCE: the openFDA record retrieved for 'estriol' was a cosmetic face cream ('Arthcal Estriol Face Cream for Women', posology field '50G/1.76OZ') and was NOT used.

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

Hypersensitivity to the active substance or to any excipient
Known, past or suspected breast cancer
Known or suspected oestrogen-dependent malignant tumours (e.g. endometrial cancer)
Undiagnosed genital bleeding
Untreated endometrial hyperplasia
Previous or current venous thromboembolism (deep venous thrombosis, pulmonary embolism)
Known thrombophilic disorders (e.g. protein C, protein S or antithrombin deficiency)
Active or recent arterial thromboembolic disease (e.g. angina, myocardial infarction)
Acute liver disease, or a history of liver disease as long as liver function tests failed to return to normal
Porphyria

Side effects

Nausea and vomiting
Breast tenderness or pain in the breasts; breast discomfort (frequency not known)
Vaginal bleeding or spotting during or on withdrawal of therapy; excessive production of cervical mucus
Headache
Application site irritation and pruritus; burning feeling/sensation in or around the genital area (frequency not known)
Dysuria and influenza-like illness (frequency not known). The SPC notes these reactions are usually transient but may also indicate too high a dosage

Clinical monograph

How it works

It binds oestrogen receptors in urogenital tissue, restoring vaginal epithelium, pH and local blood flow with comparatively weak systemic oestrogenic effect.

Prescribing in practice

Avoid in current, past or suspected breast cancer and other oestrogen-dependent malignancies, undiagnosed vaginal bleeding, and active or recent venous thromboembolism.
Investigate any unexpected or postmenopausal vaginal bleeding before continuing therapy.
Used at the lowest effective dose for the shortest duration appropriate, reviewing the need to continue periodically as per current prescribing references.

Monitoring

Review symptoms and overall HRT risk at regular intervals, and promptly assess any abnormal vaginal bleeding.

Counselling the patient

For vaginal preparations, follow the application instructions and review with your clinician periodically.
Report any unexpected vaginal bleeding.
Attend routine breast and cervical screening as recommended.

Evidence & guidelines

Use aligns with NICE menopause guidance recommending vaginal oestrogen for urogenital atrophy.

Reference: NICE NG23; British Menopause Society; 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).

Curated clinical cross-links plus same-class fallbacks.

Pathways