Two medicines, side by side
Anastrozole vs exemestane
Anastrozole and exemestane are both labeled for breast cancer. Drugs@FDA records approvals of anastrozole since 1995 and of exemestane since 1999. Pharmacies paid $0.142 per anastrozole 1 mg tablet and $0.748 per exemestane 25 mg tablet (NADAC, October 7, 2026); the strengths differ, so the two prices are not like for like. How each works, in its label's words: Anastrozole, “The growth of many cancers of the breast is stimulated or maintained by estrogens.”; Exemestane, “Aromatase is the principal enzyme that converts androgens to estrogens both in pre- and postmenopausal women.”
Check it at the source: the anastrozole FDA label on DailyMed (effective March 2, 2026); the exemestane FDA label on DailyMed (effective September 12, 2024).
Highlights of the anastrozole record
Anastrozole (Arimidex) · label of March 2, 2026
Used for
From the label: indicationsARIMIDEX is an aromatase inhibitor indicated for: • Adjuvant treatment of postmenopausal women with hormone receptor-positive early breast cancer ( 1.1 ) • First-line treatment of postmenopausal women with hormone receptor-positive or hormone receptor-unknown locally advanced or metastatic breast cancer ( 1.2 ) • Treatment of advanced breast cancer in postmenopausal women with disease progression following tamoxifen therapy. […]
On the market
- Earliest approval on file
- December 27, 1995
- Generic labelers
- 24 labelers
- Pharmacy cost
- $0.142 per tablet
Supply and safety
- Shortage
- No current entry
- Recalls
- 4
Highlights of the exemestane record
Exemestane (Aromasin) · label of September 12, 2024
Used for
From the label: indicationsExemestane tablets are an aromatase inhibitor indicated for: adjuvant treatment of postmenopausal women with estrogen-receptor positive early breast cancer who have received two to three years of tamoxifen and are switched to exemestane tablets for completion of a total of five consecutive years of adjuvant hormonal therapy ( 14.1 ). treatment of advanced breast cancer in postmenopausal women whose disease has […]
On the market
- Earliest approval on file
- October 21, 1999
- Generic labelers
- 10 labelers
- Pharmacy cost
- $0.748 per tablet
Supply and safety
- Shortage
- No current entry
- Recalls
- 0
Source: FDA drug labels via openFDA (Anastrozole label of March 2, 2026, Exemestane label of September 12, 2024); NDC Directory, Drugs@FDA, NADAC, FDA shortages and recalls (October 8, 2026)
How do anastrozole and exemestane differ on the record?
How each works, in its label's words: Anastrozole, “The growth of many cancers of the breast is stimulated or maintained by estrogens.”; Exemestane, “Aromatase is the principal enzyme that converts androgens to estrogens both in pre- and postmenopausal women.”
Both are in FDA's class aromatase inhibitors.
Half-life, in each label's words: Anastrozole, “The mean elimination half-life of anastrozole is 50 hours.”; Exemestane, “12.3 Pharmacokinetics Following oral administration to healthy postmenopausal women, plasma concentrations of …”
Generics: anastrozole since 2010; exemestane since 2011 (Drugs@FDA).
| Anastrozole | Exemestane | |
|---|---|---|
| Labeled for | Breast cancer | Breast cancer |
| Pharmacologic class | Aromatase Inhibitor | Aromatase Inhibitor |
| How it works (label) | The growth of many cancers of the breast is stimulated or maintained by estrogens. | Breast cancer cell growth may be estrogen-dependent. Aromatase is the principal enzyme that converts androgens to estrogens both in pre- and postmenopausal women. |
| Half-life (label) | The mean elimination half-life of anastrozole is 50 hours. | 12.3 Pharmacokinetics Following oral administration to healthy postmenopausal women, plasma concentrations of exemestane decline polyexponentially with a mean terminal half-life of about 24 hours. |
| Earliest approval on file (Drugs@FDA) | December 27, 1995 | October 21, 1999 |
| First generic approved | June 28, 2010 | April 1, 2011 |
| Generic labelers (NDC) | 24 labelers | 10 labelers |
| Pharmacy cost (NADAC, each one's most listed form; strengths differ) | $0.142 per tablet (Anastrozole 1 mg tablet) | $0.748 per tablet (Exemestane 25 mg tablet) |
| 12-month price change | +3% | +7% |
| Boxed warning | No | No |
| Shortage now | No current entry | No current entry |
| Recalls recorded | 4 | 0 |
| FAERS reports (a report is not proof of cause; counts follow how widely a medicine is used) | 36,521 | 21,298 |
| DEA schedule | none | none |
Source: Drugs@FDA, FDA NDC Directory, CMS NADAC of October 7, 2026, FDA shortages and recalls, FAERS via openFDA (FDA files October 8, 2026)
What next?
- Alternatives to anastrozole
- every medicine labeled for the same conditions