Femara (letrozole) is a prescription drug used to treat certain types of breast cancer in people who have gone through menopause. The drug comes as an oral tablet. Femara is not safe to take while pregnant or breastfeeding.

Keep reading to learn more about Femara and reproductive health. And for a detailed overview of this drug, check out this article.

If you can become pregnant, it’s important to consider whether Femara is a safe option for you.

You should not take Femara while pregnant. And you should not become pregnant for at least 3 weeks after your last dose of the drug. Reports of Femara use involving pregnant people suggest the drug may cause problems with fetal development (commonly known as birth defects) and pregnancy loss.

Note that Femara is not approved to treat breast cancer in people who haven’t gone through menopause yet.

Femara and fertility

Femara is sometimes prescribed as an off-label treatment for infertility. (With off-label use, a drug is prescribed for a condition it isn’t approved to treat.)

Femara does not increase the risk of fetal development or pregnancy loss when taken to help treat infertility. For this use, Femara is only taken for a few days after the start of your period. This temporarily lowers your estrogen level which helps to trigger ovulation.

The risks of fetal development or pregnancy loss only occur if the drug is taken when you’re already pregnant.

If you’re currently breastfeeding or planning to do so, it’s important to understand the effects Femara could have on you or your child.

You should not take Femara while breastfeeding. And you should not breastfeed for at least 3 weeks after your last dose of the drug.

If you’re breastfeeding or considering breastfeeding, talk with your doctor. They can recommend treatment options for you other than Femara.

If you’re sexually active and you or your partner can become pregnant, it’s important to consider how Femara could affect your birth control options.

While it’s not been shown that Femara affects birth control, some birth control drugs could make Femara less effective. You should not take or use any medications or contraceptives that contain estrogen during treatment with Femara.

Examples include:

For information on other substances that may interact with Femara, check out this article.

Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.