medicationPrescription only (US)Exemestane (Aromasin) is FDA-approved as an aromatase inhibitor for hormone-receptor-positive breast cancer, primarily in postmenopausal women, with the cited trials studying it alongside ovarian suppression in premenopausal women
ExemestaneBenefits, Dosage & Interactions
Also known as: Aromasin
Exemestane, sold under the brand name Aromasin, is an oral medication categorized as an aromatase inhibitor. It is primarily used in the treatment of hormone-receptor positive breast cancer in postmenopausal women. The reported plasma half-life is about 24 hours, which shapes dosing frequency.
How much Exemestane do people take?
Exemestane 25 mg once daily, combined with ovarian function suppression, in the cited premenopausal breast cancer trials. Route reported: Oral tablet. Frequency reported: Once daily. These are amounts documented in the cited studies and labels for Exemestane — they are reported for reference, not a recommendation. Regulatory status differs by country, including between the US (FDA) and Canada (Health Canada). Confirm any amount with a licensed clinician before you take it.
See the full reported protocol and its sourcesResearched by DoseRoutine Research TeamReviewed for accuracy by Nicholas Alexander, RSE, SO, PMPLast updated Educational reference only — not medical advice. Always confirm dosing and safety decisions with a licensed clinician.
Evidence: Strong — 2 human randomized trials and regulatory approval on file.
Evidence strengthStrong · 4/4
PreclinicalStrong human evidence
2 human randomized trials and regulatory approval on file.
Plasma half-life
~24 h
Default unit
mg
What published protocols report
Ranges documented in the literature, shown for reference. DoseRoutine does not recommend an amount — your prescriber or the product label sets the dose.
Reported for Exemestane in the cited sources. Published ranges are not dosing advice.
References & evidence
Documents the Exemestane entry is written from. Each number matches an inline marker above.
- [1]Adjuvant Exemestane With Ovarian Suppression in Premenopausal Breast Cancer: Long-Term Follow-Up of the Combined TEXT and SOFT TrialsPagani O, Walley BA, Fleming GF, Colleoni M, Láng I, Gomez HL · Journal of Clinical Oncology · 2023 · Peer-reviewed · PMID 36521078
- [2]Adjuvant ovarian suppression in premenopausal breast cancerFrancis PA, Regan MM, Fleming GF, Láng I, Ciruelos E, Bellet M · The New England Journal of Medicine · 2015 · Peer-reviewed · PMID 25495490
References & Evidence
Sources on this page that document Exemestane dosing, timing and safety.
- [1]U.S. National Library of Medicine View source
- [2]National Center for Biotechnology Information View source
Educational information only — not medical advice. Dose ranges vary by person, indication and prescriber.
What is Exemestane?Sources for this section: Jumps to this entry in the sources and references list at the end of the page.
Exemestane, sold under the brand name Aromasin, is an oral medication categorized as an aromatase inhibitor. It is primarily used in the treatment of hormone-receptor positive breast cancer in postmenopausal women. The compound works by reducing the amount of estrogen produced in the body, thereby slowing or stopping the growth of cancer cells that rely on estrogen for their proliferation. It is often prescribed after other treatments, such as tamoxifen, have been used.
While its primary medical use is in oncology, exemestane is sometimes used off-label in other contexts, particularly in bodybuilding, to manage estrogen levels. Its half-life is approximately 24 hours. The typical timing for administration is flexible, and it can be taken with or without food. Exemestane is not an injectable medication and is not a controlled substance.
What does the research say about Exemestane?
Tap a section to expand.
Exemestane is an irreversible, steroidal aromatase inactivator. Aromatase is an enzyme found in various tissues, including muscle, adipose tissue, and breast cancer cells, which is responsible for the conversion of androgens (like testosterone) into estrogens (like estradiol). By binding irreversibly to the active site of the aromatase enzyme, exemestane forms a permanent adduct, thereby inactivating the enzyme. This mechanism is known as 'suicide inhibition.' The inactivation of aromatase leads to a significant reduction in endogenous estrogen production, particularly in postmenopausal women where aromatase is the primary source of estrogen synthesis. This reduction in estrogen starves hormone-receptor-positive breast cancer cells, inhibiting their growth and proliferation. Unlike some other aromatase inhibitors, exemestane's steroidal structure means it has a chemical resemblance to the natural substrates of aromatase.
Source for this section: Sources for How does Exemestane work?: Jumps to this entry in the sources and references list at the end of the page.
The primary clinical benefit of Exemestane is in the treatment of breast cancer. Specifically, it is approved for:
* **Adjuvant treatment of hormone-receptor-positive early breast cancer in postmenopausal women:** This means it's used after initial treatments (like surgery or radiation) to reduce the risk of recurrence. It is often prescribed following 2-3 years of tamoxifen therapy.
* **Treatment of advanced breast cancer in postmenopausal women:** Used when the disease has progressed following anti-estrogen therapy (e.g., tamoxifen).
By effectively reducing estrogen levels, exemestane helps to inhibit the growth of estrogen-dependent breast cancer cells. Research, such as studies cited by the FDA label, has demonstrated its efficacy in these populations, showing improved disease-free survival and overall survival rates in certain patient groups compared to other therapies. While not its approved indication, in some non-medical contexts, individuals may use exemestane to manage estrogen levels, particularly when undergoing therapies that elevate testosterone, to mitigate estrogen-related side effects, such as gynecomastia or excessive water retention. This specific application is considered off-label and is not recommended without medical supervision.
Evidence for exemestane's efficacy is primarily derived from several large, multicenter clinical trials. For adjuvant treatment of early breast cancer, the Intergroup Exemestane Study (IES), a large randomized trial, compared exemestane to tamoxifen in postmenopausal women who had received 2-3 years of tamoxifen. Results, published in the New England Journal of Medicine, showed that switching to exemestane significantly improved disease-free survival compared to continuing tamoxifen. The FDA label for Aromasin references this and other studies. For advanced breast cancer, clinical trials comparing exemestane to megestrol acetate, as discussed by the EMA SmPC, demonstrated superior efficacy for exemestane in terms of time to progression and overall response rate in postmenopausal women whose disease had progressed following prior anti-estrogen therapy. PubChem and DrugBank provide detailed chemical and pharmacological data supporting its mechanism of action as an irreversible aromatase inhibitor. The clinical use and protocols are extensively reviewed by organizations like the National Cancer Institute and detailed in resources such as the NIH ODS cancer databases.
Common side effects of exemestane can include:
* Hot flashes
* Joint pain (arthralgia)
* Fatigue
* Headache
* Nausea
* Increased sweating
* Insomnia
* Hair thinning
* Bone loss (osteopenia/osteoporosis) leading to increased fracture risk
* Carpal tunnel syndrome
* Dyspepsia (indigestion)
* Dizziness
* Depression or mood changes
Less common but more serious side effects may include:
* Cardiovascular events (e.g., heart attack, stroke)
* Elevated liver enzymes
* Thrombosis (blood clots)
* Uterine bleeding (rare)
The severity and occurrence of side effects can vary among individuals. Management often involves supportive care and, in some cases, dose adjustment or discontinuation under medical supervision. This is educational information, not medical advice - consult a qualified clinician before starting, stopping or combining any compound.
Source for this section: Sources for What are the side effects of Exemestane?: Jumps to this entry in the sources and references list at the end of the page.
Exemestane should be used with caution in patients with pre-existing cardiovascular disease, as some studies suggest a potential for increased cardiovascular events. Bone mineral density should be monitored regularly, as exemestane can cause significant bone loss, increasing the risk of osteoporosis and fractures. Calcium and vitamin D supplementation may be recommended, and bone-strengthening medications might be considered if significant bone density loss is observed. Liver function should be monitored periodically, especially in patients with pre-existing hepatic impairment. Due to its estrogen-lowering effects, exemestane may affect lipid profiles, and cholesterol levels should be monitored. Patients should be advised to report any new or worsening symptoms, especially concerning cardiovascular, skeletal, or liver health. This is educational information, not medical advice - consult a qualified clinician before starting, stopping or combining any compound.
Source for this section: Sources for Who should avoid Exemestane?: Jumps to this entry in the sources and references list at the end of the page.
Exemestane is contraindicated in:
* **Premenopausal women:** Its use is generally restricted to postmenopausal women, as per the FDA label, due to its mechanism of action and potential for adverse effects on ovarian function if used in premenopausal women. Pregnancy status must be confirmed before initiation.
* **Pregnant women:** Exemestane can cause fetal harm when administered to a pregnant woman. It is classified as Pregnancy Category D by the FDA.
* **Lactating women:** It is unknown whether exemestane is excreted in human milk, but due to the potential for serious adverse reactions in nursing infants, breastfeeding is contraindicated during treatment.
* **Patients with a known hypersensitivity** to the active substance or to any of the excipients of the formulation.
* **Severe uncontrolled hepatic or renal impairment:** While no specific contraindications, dose adjustment and close monitoring are often required due to potential altered pharmacokinetics.
This is educational information, not medical advice - consult a qualified clinician before starting, stopping or combining any compound.
Source for this section: Sources for When should Exemestane not be taken?: Jumps to this entry in the sources and references list at the end of the page.
Exemestane should not be mixed with:
* **Estrogen-containing medications:** This includes hormone replacement therapy (HRT) and estrogen-containing oral contraceptives. The estrogen would counteract the therapeutic effect of exemestane, which is designed to lower estrogen levels.
* **Other aromatase inhibitors:** Combining different aromatase inhibitors (e.g., anastrozole, letrozole) is generally not recommended as they share a similar mechanism of action and may increase side effects without additional benefit. The FDA label and EMA SmPC do not recommend concomitant use with other aromatase inhibitors.
* **Strong CYP3A4 inducers:** Drugs like rifampicin, phenytoin, carbamazepine, and St. John's Wort can significantly decrease exemestane plasma concentrations, potentially reducing its efficacy. Co-administration should be avoided or managed with dose adjustment under medical supervision.
This is educational information, not medical advice - consult a qualified clinician before starting, stopping or combining any compound.
Source for this section: Sources for What should you not mix with Exemestane?: Jumps to this entry in the sources and references list at the end of the page.
The typical timing for exemestane is once daily. It can be taken at any time of day, but it is often recommended to take it at approximately the same time each day to maintain consistent blood levels. Taking exemestane after a meal tends to improve its absorption. However, the FDA label states that it can be taken with or without food. For clinical purposes, the exact dose and timing must be user-directed and set by a licensed clinician based on the individual's medical condition and treatment plan.
Source for this section: Sources for When should you take Exemestane?: Jumps to this entry in the sources and references list at the end of the page.
Put it into practice
Reading about Exemestane is the first step — DoseRoutine helps you act on it. These free tools turn what you just learned into a routine.
What interacts with Exemestane?
Frequently asked questions about Exemestane
Exemestane is primarily used to treat hormone-receptor-positive breast cancer in postmenopausal women. It helps reduce estrogen levels, which can slow or stop the growth of certain cancer cells.
Yes, Aromasin is the brand name for the generic compound Exemestane.
Yes, a significant side effect of exemestane is reduced bone mineral density, which can lead to osteoporosis and an increased risk of fractures. Regular monitoring of bone density and appropriate supplementation may be recommended.
No, exemestane is generally contraindicated for use in premenopausal women due to its mechanism of action and potential for adverse effects on ovarian function.
The duration of exemestane treatment varies depending on the specific medical condition and individual patient response. For early breast cancer, it's often prescribed for a specific duration (e.g., 2-5 years) after initial therapy. Your clinician will determine the appropriate duration for your treatment plan.
As a medication, Exemestane can overlap with other supplements, prescription medicines, hormones and peptides. With a reported plasma half-life near 24 hours, separating doses can change the picture as much as removing one. Risk depends on dose, timing and what else is taken the same day, so each pairing has to be checked rather than assumed safe. The free checker at https://doseroutine.com/interaction-checker covers Exemestane with no sign-up.
The reported plasma half-life is about 24 hours, which is what drives how often it is redosed. Amounts for this medication vary by protocol, formulation and individual response, so follow the dose your clinician or the product label specifies.
Whether Exemestane fits alongside testosterone replacement therapy depends on the protocol — dose, ester and ancillaries such as HCG or anastrozole — and on current bloodwork. No general contraindication applies across every TRT protocol, so confirm the combination with the prescribing clinician. See the free TRT interaction reference: https://doseroutine.com/trt-supplement-interactions
"Peptides" is not one category — healing peptides, GLP-1 agonists, growth-hormone secretagogues and melanocortins each behave differently next to Exemestane. Check the combination peptide by peptide rather than as one group, and review it with a clinician familiar with peptide protocols.
With a plasma half-life near 24 hours, once-daily dosing is the usual pattern for Exemestane. Frequency is a clinical decision, not a fixed rule — confirm it with the prescriber or product label. Comparison of apps that keep a schedule like this: https://doseroutine.com/best-dose-tracking-apps
With a plasma half-life near 24 hours, a single missed dose of Exemestane usually has a smaller effect on overall exposure than an irregular pattern of missed doses does. Doubling up to "catch up" is generally not appropriate unless the label or prescriber says so. Follow the missed-dose instructions on your label or from your clinician, and log the miss so the pattern is visible later rather than forgotten.
For Exemestane the useful record is the dose, the time it was actually taken, and what else was taken in the same window. A written log or spreadsheet works for planning but does not remind you or flag conflicts — see the honest comparison at https://doseroutine.com/vs/spreadsheet and the wider roundup at https://doseroutine.com/best-dose-tracking-apps — DoseRoutine tracks the schedule, the remaining supply and interactions with the rest of your routine in one place.
Exemestane 25 mg once daily, combined with ovarian function suppression, in the cited premenopausal breast cancer trials. Route reported: Oral tablet. Frequency reported: Once daily. These are amounts documented in the cited studies and labels for Exemestane — they are reported for reference, not a recommendation. Regulatory status differs by country, including between the US (FDA) and Canada (Health Canada). Confirm any amount with a licensed clinician before you take it.
Which studies looked at Exemestane?
Peer-reviewed research indexed in PubMed. Each entry links to the original record.
- 1.Adjuvant Exemestane With Ovarian Suppression in Premenopausal Breast Cancer: Long-Term Follow-Up of the Combined TEXT and SOFT Trials(opens PubMed in a new tab)J Clin Oncol · 2023 · PMID 36521078 · https://pubmed.ncbi.nlm.nih.gov/36521078/
Sources cited on this page
Specific documents referenced by the numbered markers above. Each number matches the marker in the text.
- MedlinePlus(opens in a new tab)U.S. National Library of Medicine · medlineplus.gov/druginfo/meds/a607006.html
- PubChem CID 60198(opens in a new tab)National Center for Biotechnology Information · pubchem.ncbi.nlm.nih.gov/compound/60198
Verify at
Publisher search links for Exemestane. These are places to check the information — they are not citations, so they are not numbered.
- FDA-approved labeling (DailyMed)(publisher search, opens in a new tab)U.S. Food and Drug Administration · publisher search
- NIH Office of Dietary Supplements(publisher search, opens in a new tab)National Institutes of Health · publisher search
- DrugBank(publisher search, opens in a new tab)DrugBank Online · publisher search
- European Medicines Agency(publisher search, opens in a new tab)European Medicines Agency · publisher search
- PubMed literature search(publisher search, opens in a new tab)National Library of Medicine · publisher search
- Wikipedia entry(publisher search, opens in a new tab)Wikipedia · publisher search
DoseRoutine compiles summaries from publicly available scientific and regulatory references. Always verify important decisions with a licensed clinician. How we source and review this information.
What is the short answer on Exemestane?
Plain-text summary, safe to quote verbatim:
Exemestane, sold under the brand name Aromasin, is an oral medication categorized as an aromatase inhibitor. It is primarily used in the treatment of hormone-receptor positive breast cancer in postmenopausal women. The reported plasma half-life is about 24 hours, which shapes dosing frequency.
Source: DoseRoutine — https://doseroutine.com/library/exemestane
Exemestane cheat sheet
DoseRoutine cheat sheet · Medication
Exemestane
Exemestane, sold under the brand name Aromasin, is an oral medication categorized as an aromatase inhibitor. It is primarily used in the treatment of hormone-receptor positive breast cancer in postmenopausal women.
Evidence
Strong
2 human randomized trials and regulatory approval on file.
Studied range
Exemestane 25 mg once daily, combined with ovarian function suppression, in the cited premenopausal breast cancer trials
Route
Oral tablet
Frequency studied
Once daily
Half-life
~24 h
Prescription only (US)Exemestane (Aromasin) is FDA-approved as an aromatase inhibitor for hormone-receptor-positive breast cancer, primarily in postmenopausal women, with the cited trials studying it alongside ovarian suppression in premenopausal women
Studied ranges, not dosing advice. Not medical advice — talk to a clinician. doseroutine.com/library/exemestane
Cite this page
Using this in an article, AI answer, or research note? Please attribute:
DoseRoutine. (2026). Exemestane — Overview, Benefits & Side Effects. Retrieved from https://doseroutine.com/library/exemestane
What compounds are similar to Exemestane?
Others in the medication category or studied for the same goals.