Ovesterin (Estriol)

• Estriol acts as a local estrogen to restore vaginal tissue integrity and relieve menopausal genital symptoms.
• Vulvovaginal atrophy: reduces dryness, itching, and irritation of the vaginal mucosa.
• Menopausal dyspareunia: lessens pain during sexual intercourse caused by estrogen deficiency.
• Postmenopausal urinary symptoms: may improve frequency, urgency and mild incontinence associated with atrophic changes.

• Estriol binds to estrogen receptors (ERα and ERβ) in vaginal epithelium, stimulating cellular proliferation and increasing glycogen production. This restores mucosal thickness, improves vascularization, and enhances lubrication, thereby normalizing the local microenvironment and alleviating atrophic symptoms.

Estriol may cause a range of adverse reactions, most of which are mild and reversible.

Common Side Effects

• Vaginal irritation or burning sensation
• Light vaginal spotting or discharge
• Headache
• Breast tenderness
• Nausea or mild gastrointestinal upset
• Mild abdominal cramping

Serious or Rare Side Effects

• Endometrial hyperplasia or abnormal uterine bleeding
• Thromboembolic events (deep vein thrombosis, pulmonary embolism)
• Severe allergic reaction (rash, swelling, anaphylaxis)
• Significant vaginal bleeding
• Carcinogenic risk with prolonged high‑dose use

Estriol therapy requires careful assessment of individual risk factors and contraindications.

• Contraindications: known estrogen‑dependent neoplasia or active breast cancer.
• Thromboembolic risk: avoid in patients with personal or family history of clotting disorders.
• Hepatic impairment: use with caution in severe liver disease.
• Pregnancy and lactation: not recommended due to hormonal activity.
• Monitor for abnormal vaginal bleeding and report promptly.
• Store at room temperature: keep in the original container, protect from moisture and light.

Estriol can interact with other medications that affect hormonal balance or coagulation pathways.

Major Interactions (Avoid)

• Combined oral contraceptives containing estrogen: increased thrombotic risk.
• Concurrent systemic estrogen therapy: additive estrogenic effects.
• Anticoagulants (warfarin, DOACs): potential enhancement of bleeding.

Moderate Interactions (Monitor Closely)

• Tamoxifen or other selective estrogen receptor modulators: may reduce anti‑estrogen efficacy.
• SSRIs and SNRIs: may influence perception of menopausal symptoms.
• Antifungal vaginal preparations: could alter local estriol absorption.