Femara is the brand name for the drug letrozole which belongs to a class of aromatase inhibitors. It is used clinically to treat hormone dependent breast cancer in postmenopausal women by reducing estrogen production. The medication works by blocking the aromatase enzyme that converts androgens into estrogen in peripheral tissues. Inhibition of this enzyme leads to lower circulating estrogen levels which slows the growth of estrogen sensitive tumor cells. This mechanism provides a therapeutic benefit by limiting hormone driven disease progression while sparing tissues that rely on androgen conversion. The drug is administered orally and its anti estrogenic effect is achieved through systemic absorption and pharmacologic inhibition of aromatase.

Femara is a nonsteroidal aromatase inhibitor used in the treatment of hormone receptor positive breast cancer. It works by decreasing the conversion of androgens to estrogen in peripheral tissues. By lowering systemic estrogen levels it slows the growth of estrogen dependent tumor cells. The reduction of estrogen triggers apoptosis in malignant cells and inhibits their proliferation. Femara's selective inhibition of aromatase results in decreased estrogen availability without directly affecting other hormonal pathways. This mechanism provides clinical benefit in postmenopausal women whose tumors rely on estrogen signaling.

The most common side effects include nausea dizziness fatigue and headache. These reactions are generally mild and short lived in most individuals. Nausea often appears shortly after taking the medication and may improve with food. Dizziness can be accompanied by a feeling of lightheadedness or unsteadiness. Fatigue may be experienced as a general sense of low energy without specific cause. Headache typically presents as a mild to moderate pressure in the forehead or temples. Some people report mild stomach discomfort that usually resolves without intervention. Overall these effects tend to diminish as the body adjusts to the treatment.

Headache is often reported among users of certain medications. Nausea follows as a frequent accompanying symptom. Fatigue can occur after initial dosing. Dry mouth may affect comfort during use. Dizziness sometimes appears after physical activity. Mild skin irritation may develop at application sites. Insomnia may interrupt normal sleep patterns.