What it is
A steroidal irreversible aromatase inactivator available as an oral tablet.
How it works
An androstenedione analog that binds covalently to the active site of aromatase (CYP19), permanently inactivating the enzyme and reducing peripheral conversion of androgens to estrogens.
Where it's used
Used in postmenopausal women with estrogen-receptor-positive breast cancer. Off-label, sometimes used by clinicians to manage elevated estradiol in men on testosterone therapy.
FDA-approved use
Adjuvant treatment of estrogen-receptor-positive early breast cancer and treatment of advanced breast cancer in postmenopausal women.
Tracking it
Exemestane is oral, which makes consistency the whole game — a simple daily check-off with a reminder beats memory every time. with a half-life of about 24 hours, a dose log also lets a tracker model the relative amount still in your system between doses.
Source
OpenFDA
Last reviewed 2026-06-11