Key points
- Exemestane is a 25 mg tablet taken once a day after a meal [1].
- It lowers oestrogen production in women after menopause so that hormone receptor-positive breast cancer does not come back or grow [1].
- In younger women it is used together with a drug that switches off the ovaries [3].
- It puts a strain on the bones; bone density scans, calcium and vitamin D are needed.
What is this drug and how does it work?
After menopause, most oestrogen is made in fat tissue by an enzyme called aromatase. Exemestane switches this enzyme off permanently [1].
For physicians
An irreversible, steroidal aromatase inhibitor (type 1 inactivator) [1].
Which cancers is it used for?
For physicians
| Disease | Use | Key evidence |
|---|---|---|
| Early breast cancer, after 2 to 3 years of tamoxifen | Switch to exemestane | IES: longer disease-free survival than continuing tamoxifen [2] |
| Premenopausal, high risk | With ovarian suppression | SOFT/TEXT: fewer recurrences than tamoxifen with ovarian suppression [3] |
| Advanced, after a non-steroidal inhibitor | With everolimus | BOLERO-2: longer progression-free survival [4] |
How it is taken and dosing
Show detailsHide
One 25 mg tablet a day, after a meal [1]. It usually continues for 5 years (sometimes longer).
For physicians
Standard dosing (FDA label)
Exemestane
HR+ breast cancer in postmenopausal womenCycle length: Daily
HR+ breast cancer in postmenopausal women
| Drug | Dose | Route | Schedule |
|---|---|---|---|
| Exemestane | 25 mg once daily | Oral, after a meal | Daily |
Doses follow the trial protocol, guideline or official drug label (source given in the notes of each regimen). Before prescribing, check blood counts, renal and hepatic function, drug interactions and the patient’s condition, and adjust the dose according to the drug label.
Side effects
The most common side effects: hot flushes, tiredness, joint pain, headache, trouble sleeping and sweating [1].
For physicians
Hot flushes, fatigue, arthralgia, headache, insomnia, sweating; decreased bone mineral density and raised cholesterol [1].
Serious side effects
Less common serious side effects: loss of bone density and fractures [1].
For physicians
- Bone density: baseline and periodic measurement; calcium, vitamin D and a bone-protective drug if needed (bone health lesson).
- Not effective in premenopausal women without ovarian suppression [1].
When should I call my doctor?
- Bone pain or a fracture after a minor knock
- Severe joint pain that disrupts daily activities
- Unusual bleeding
Interactions, pregnancy and precautions
- Other medicines: do not take oestrogen-containing products with it; rifampicin and epilepsy medicines reduce its effect [1].
- Pregnancy: this drug may harm an unborn baby; use effective contraception during treatment and tell your doctor straight away if you become pregnant. Do not breastfeed during treatment [1].
Frequently asked questions
What can I do about joint pain?
Regular exercise and simple painkillers help; if it is severe, talk to your doctor about another drug and do not stop on your own.
Related cancer types
References
4 referencesShow all references, 1 with a study cardClose the reference list
Numbers in the text, such as [1], refer to these sources. Sources with a “Study card” button are summarised in the site’s evidence library.
- 1
- 2
- 3
- 4Everolimus in postmenopausal hormone-receptor-positive advanced breast cancer
This page is based on reputable scientific sources and was last updated on 27 October 2026. The content of this website is for educational and informational purposes only and does not replace consultation, diagnosis or treatment by a specialist physician. Consult your treating physician about any treatment decision.
Printed from the website; the full and up-to-date version: https://drdabiri.com/en/drugs/exemestane/