Exemestane (exemestane)
Multiple manufacturers (generic); original brand: Aromasin by Pfizer · Aromatase Inactivator / Steroidal Aromatase Inhibitor
What is Exemestane? Exemestane (brand: Aromasin) is a steroidal aromatase inactivator used in the adjuvant treatment of postmenopausal women with early breast cancer and for advanced or metastatic breast cancer. It permanently and irreversibly inactivates the aromatase enzyme.
About Exemestane
| Brand Name | Exemestane |
| Generic / INN | exemestane |
| Drug Class | Aromatase Inactivator / Steroidal Aromatase Inhibitor |
| Manufacturer | Multiple manufacturers (generic); original brand: Aromasin by Pfizer |
| Administration | Oral tablet |
| FDA Approval | 1999 |
FDA-Approved Uses for Exemestane
Indications are based on FDA approval. Your healthcare provider determines appropriate use based on your specific diagnosis, stage, biomarker status, and overall clinical picture.
- Early breast cancer — adjuvant treatment of postmenopausal women with ER-positive early breast cancer after 2–3 years of tamoxifen
- Advanced breast cancer — treatment of postmenopausal women with ER-positive advanced or metastatic breast cancer after tamoxifen failure
How Does Exemestane Work?
Exemestane is a steroidal aromatase inactivator (also called a type I aromatase inhibitor) that irreversibly and permanently binds to and inactivates the aromatase enzyme. Aromatase converts androgens to estrogens in peripheral tissues. By irreversibly inactivating aromatase, exemestane suppresses circulating estrogen levels in postmenopausal women, starving hormone receptor-positive breast cancer of its growth signal.
Dosage & Administration
25 mg orally once daily after a meal. Used in postmenopausal women. Premenopausal women being treated for hormone receptor-positive breast cancer typically require ovarian suppression in addition to exemestane.
Dosing is individualized by the prescribing clinician. Never adjust your dose without consulting your healthcare provider. This information is educational only and does not replace the official prescribing information.
Warnings, Precautions & Side Effects
General Warning
Bone density loss — assess bone mineral density before and during treatment; calcium and vitamin D supplementation and bisphosphonates may be needed. Not for use in premenopausal women without ovarian suppression. Embryo-fetal toxicity (highly teratogenic). Elevated liver enzymes reported.
- Bone mineral density loss
- Embryo-fetal toxicity (teratogenic)
- Hepatotoxicity (rare)
Common Side Effects
- Hot flashes
- Fatigue
- Arthralgia
- Arthritis
- Joint pain and stiffness
- Headache
- Depression
- Insomnia
- Peripheral edema
This is not a complete list. Always report new or worsening symptoms to your healthcare provider promptly.
Storage & Handling
Store at room temperature 25°C (77°F); excursions permitted to 15°C to 30°C (59°F to 86°F).
BiologicHealthPlus provides temperature-monitored cold-chain specialty delivery for medications requiring refrigeration. Never use a medication if its storage conditions have been compromised.
Insurance Coverage, Prior Authorization & Patient Assistance
🛡️ Commercial Insurance
Exemestane is covered by most major commercial insurance plans when medically necessary and prior authorized. Coverage tier and cost-sharing vary by plan.
✅ Prior Authorization
Prior authorization is required by virtually all insurance plans for Exemestane. BiologicHealthPlus handles the complete prior authorization process at no cost to patients or providers.
🏥 Medicare Coverage
Medicare Part D covers this oral specialty medication. Medicaid coverage varies by state.
🆓 Patient Assistance
Manufacturer patient assistance programs may be available for eligible uninsured or underinsured patients. Contact BiologicHealthPlus for a confidential eligibility review.
Prior Authorization Patient Assistance Insurance & Savings Medication Costs
Frequently Asked Questions — Exemestane
Exemestane (brand: Aromasin) is used to treat hormone receptor-positive (ER+) breast cancer in postmenopausal women — both as adjuvant therapy after tamoxifen and for advanced/metastatic disease.
Both are aromatase inhibitors, but exemestane is a steroidal, irreversible (Type I) aromatase inactivator, while anastrozole is a non-steroidal, reversible (Type II) aromatase inhibitor. Clinical outcomes are broadly similar; selection depends on tolerability and patient factors.
Yes — aromatase inhibitors including exemestane reduce estrogen levels, which accelerates bone mineral density loss. Regular bone density monitoring, calcium and vitamin D supplementation, and sometimes bisphosphonate therapy are recommended.
Yes. Generic exemestane 25 mg tablets are widely available. The original brand Aromasin is manufactured by Pfizer.
Related Medications & Conditions
Related Medications
Letrozole (Femara) · Anastrozole (Arimidex) · Tamoxifen · Verzenio (abemaciclib) · Ibrance (palbociclib)
Related Conditions
HR+ breast cancer · Early breast cancer · Metastatic breast cancer · Postmenopausal breast cancer