Letrozole lowers estrogen levels in postmenopausal women, which may slow the growth of certain types of breast tumors that need estrogen to grow in the body.
Letrozole is used to treat breast cancer in postmenopausal women. It is often given to women who have been taking tamoxifen (Nolvadex, Soltamox) for 5 years.
Letrozole can harm an unborn baby or cause birth defects. Do not use if you are pregnant. You should not use Letrozole if you are allergic to letrozole, or if you have not gone completely through menopause.
Less serious Femara side effects may include: