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Femara

Generic name: letrozole

Used for breast cancer
Last updated September 10, 2026 0 views Reviewed by Philip Thornton, DipPharm
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What is Femara?

Femara 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.

Femara 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.

How should I take Femara?

Femara is usually taken once per day, or once every other day. Follow all directions on your prescription label. Do not take this medicine in larger or smaller amounts or for longer than recommended.

You may take this medicine with or without food.

While using Femara, you may need frequent medical tests and your bone mineral density may also need to be checked.

Store at room temperature away from moisture and heat.

Warnings

Femara can harm an unborn baby or cause birth defects. Do not use if you are pregnant.

Before taking Femara, tell your doctor if you have osteoporosis, high cholesterol, or liver disease (especially cirrhosis).

Femara may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert. To be sure this medicine is helping your condition, your blood may need to be tested often. Your bone mineral density may also need to be checked. Visit your doctor regularly.

Tell your doctor about all other medicines you use, especially tamoxifen (Soltamox).

Before taking this medicine

You should not use Femara if you are allergic to letrozole, or if you have:

  • if you have not gone completely through menopause; or
  • you are pregnant.

Femara is for use only in women who can no longer get pregnant. Letrozole can harm an unborn baby. Do not use letrozole if you are pregnant. You may need to have a negative pregnancy test before starting this treatment. Use effective birth control if you are not past menopause. Keep using birth control for at least 3 weeks after your last dose of Femara. Tell your doctor if you think you may be pregnant. This medicine may affect fertility (ability to have children) in both men and women.

To make sure this medicine is safe for you, tell your doctor if you have:

  • liver disease (especially cirrhosis);
  • osteoporosis, osteopenia (low bone mineral density);
  • high cholesterol; or
  • if you also take tamoxifen.

You should not breastfeed while you are using letrozole and for at least 3 weeks after your last dose.

Femara side effects

Get emergency medical help if you have signs of an allergic reaction to Femara: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Common Femara side effects may include:

  • hot flashes, warmth or redness in your face or chest;
  • headache, dizziness, weakness;
  • bone pain, muscle or joint pain;
  • swelling, weight gain;
  • increased sweating; or
  • increased cholesterol in your blood.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Dosing information

Usual Adult Dose for Breast Cancer:

For use as first-line treatment of postmenopausal women with hormone receptor positive or hormone receptor unknown locally advanced or metastatic breast cancer. Femara is also indicated for the treatment of advanced breast cancer in postmenopausal women with disease progression following antiestrogen therapy: 2.5 mg tablet orally administered once a day without regard to meals. In patients with advanced disease, Letrozole therapy should continue until tumor progression is evident.

Usual Adult Dose for Breast Cancer - Adjuvant:

For use as extended adjuvant treatment of early breast cancer in postmenopausal women who have received 5 years of adjuvant tamoxifen therapy: 2.5 mg tablet orally administered once a day without regard to meals. The optimal duration of treatment with Femara is not known. Treatment should be discontinued if there is a tumor relapse.

What happens if I miss a dose?

Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Avoid driving or performing any hazardous activities until you know how this medicine will affect you. Your reactions could be impaired.

What other drugs will affect Femara?

Other drugs may interact with letrozole, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell each of your health care providers about all medicines you use now and any medicine you start or stop using.

Common questions about Femara

Does Femara make your hair fall out?
Femara (generic name: letrozole) can cause hair thinning, but it almost never makes all of your hair fall out. In the manufacturer's two largest breast cancer trials, 3.4% to 6.2% of women taking Femara reported hair loss, and only 0.1% had a case rated as severe. Continue reading
What are the benefits of taking Kisqali and Femara together?
Taking Kisqali and Femara together can benefit patients with specific types of breast cancer because the medications work in different ways. Kisqali blocks the growth of cancer cells, while Femara reduces the amount of estrogen in the body that can fuel cancer growth. Continue reading

Related medicines

Before you take this medicine: the information on this page is general and may not cover your personal circumstances. Read the label supplied with your medicine and ask a pharmacist or doctor if you are unsure, especially if you are pregnant, breastfeeding, taking other medicines or managing a long-term condition.
General medicine information Consumer-friendly language Source: Drugs.com

Content is provided for education and is not medical advice. See our medical disclaimer. Source page medically reviewed by Philip Thornton, DipPharm on September 10, 2026.