≥98% (HPLC)

Empirical Formula (Hill Notation):
CAS Number:
Molecular Weight:
MDL number:
PubChem Substance ID:
Pricing and availability is not currently available.

Quality Level


≥98% (HPLC)



optical activity

[α]/D +250 to +300°, c = 1 in methanol

mfr. no.



white to off-white


DMSO: ≥20 mg/mL



storage temp.


SMILES string




InChI key


Gene Information

human ... CYP19A1(1588)

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Related Categories


5, 25 mg in glass bottle

Biochem/physiol Actions

Exemestane is a steroidal antiestrogen and irreversible aromatase inhibitor. Exemestane acts as a false substrate for the aromatase enzyme. Exemestane also prevents the conversion of androgens to estrogens and is used to treat estrogen-dependent breast cancer.

Features and Benefits

This compound is featured on the Nuclear Receptors (Steroids) page of the Handbook of Receptor Classification and Signal Transduction. To browse other handbook pages, click here.
This compound is also offered as part of Sigma′s Library of Pharmacologically Active Compounds (LOPAC®Pfizer), a collection of 90 Pfizer-developed drugs and research tools. Click here to learn more.

Other Notes

This compound was developed by Pfizer for Cytokines & Growth Factors research. To learn more about Sigma′s partnership with Pfizer and view other authentic, high-quality Pfizer compounds, visit sigma.com/bsm-pfizer.

To browse the list of other pharma-developed compounds and Approved Drugs/Drug Candidates, click here.

Legal Information

Sold for research purposes under agreement from Pfizer Inc.
LOPAC is a registered trademark of Sigma-Aldrich Co. LLC
Pfizer is a registered trademark of Pfizer, Inc.


Health hazardEnvironment

Signal Word


Hazard Statements


NONH for all modes of transport

WGK Germany


Flash Point(F)

Not applicable

Flash Point(C)

Not applicable

Certificate of Analysis
Certificate of Origin
Nan Soon Wong et al.
Expert opinion on pharmacotherapy, 6(13), 2353-2363 (2005-10-13)
Breast cancer is a major health problem in developed countries. Endocrine therapy is a key component in the management of hormone receptor-positive disease. Although tamoxifen has historically been the gold standard in the first-line management of early and advanced breast...
Willemien van de Water et al.
The oncologist, 18(1), 8-13 (2012-12-25)
For postmenopausal patients with hormone-sensitive breast cancer, outcome is worse with increasing age at diagnosis. The aim of this study was to assess the incidence of breast cancer recurrence (locoregional and distant), and contralateral breast cancer by age at diagnosis....
Willemien van de Water et al.
European journal of cancer (Oxford, England : 1990), 49(2), 297-304 (2012-09-08)
Multiple studies suggest better efficacy of chemotherapy in invasive ductal breast carcinomas (IDC) than invasive lobular breast carcinomas (ILC). However, data on efficacy of adjuvant endocrine therapy regimens and histological subtypes are sparse. This study assessed endocrine therapy efficacy in...
John Fr Robertson et al.
The Lancet. Oncology, 14(3), 228-235 (2013-02-19)
Insulin-like growth factors (IGF-1 and IGF-2) bind to the IGF-1 receptor (IGF-1R), increasing cell proliferation and survival. Ganitumab is a monoclonal IgG1 antibody that blocks IGF-1R. We tested the efficacy and safety of adding ganitumab to endocrine treatment for patients...
John M S Bartlett et al.
Journal of clinical oncology : official journal of the American Society of Clinical Oncology, 30(36), 4477-4484 (2012-10-10)
Some postmenopausal patients with hormone-sensitive early breast cancer remain at high risk of relapse despite endocrine therapy and, in addition, might benefit from adjuvant chemotherapy. The challenge is to prospectively identify such patients. The Mammostrat test uses five immunohistochemical markers...

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