Generic Name: Femara Brand Name(s): Generics only. No brands available.


What is Femara® (letrozole) used for?

Femara® is commonly used to treat certain types of breast cancer (such as hormone-receptor-positive breast cancer) in women after menopause. Femara® is also used to help prevent the cancer from returning.

Some breast cancers are made to grow faster by a natural hormone called estrogen. Femara® decreases the amount of estrogen that body makes and helps to slow or reverse the growth of these breast cancers.

Femara® may be prescribed for other uses; ask your doctor or pharmacist for more information.

How should I take Femara® (letrozole)?

Femara® is usually taken once per day, or once every other day. 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 blood tests. Your bone mineral density may also need to be checked.

Ask your health care provider any questions you may have about how to use Femara®.

How do I store Femara® (letrozole)?

Femara® is best stored at room temperature away from direct light and moisture. To prevent drug damage, you should not store Femara® in the bathroom or the freezer. There may be different brands of Femara® that may have different storage needs. It is important to always check the product package for instructions on storage, or ask your pharmacist. For safety, you should keep all medicines away from children and pets.

You should not flush Femara® down the toilet or pour them into a drain unless instructed to do so. It is important to properly discard this product when it is expired or no longer needed. Consult your pharmacist for more details about how to safely discard your product.

Precautions & warnings

What should I know before using Femara® (letrozole)?

Consult with your doctor or pharmacist, if:

  • You are pregnant or breastfeeding. This is because, while you are expecting or feeding a baby, you should only take medicines on the recommendation of a doctor.
  • You are taking any other medicines. This includes any medicines you are taking which are available to buy without a prescription, such as herbal and complementary medicines.
  • You have allergy with any of active or inactive ingredients of Femara® or other medications.
  • You have any other types of allergies, such as to foods, dyes, preservatives, or animals.

Is it safe during pregnancy or breastfeeding?


There are no adequate studies in women for determining risk when using Femara® during pregnancy or while breastfeeding. Please always consult with your doctor to weigh the potential benefits and risks before taking Femara®. Femara® is pregnancy risk category D, according to the US Food and Drug Administration (FDA).

FDA pregnancy risk category reference below:

  • A=No risk
  • B=No risk in some studies
  • C=There may be some risk
  • D=Positive evidence of risk
  • X=Contraindicated
  • N=Unknown


Not known if excreted in breast milk (for post-menopausal women).

Always consult your health care provider prior to using if you are pregnant, breastfeeding.

Side effects

What side effects can occur from Femara® (letrozole)?

Here are side effects:

  • Hot flashes
  • Arthralgia
  • Flushing
  • Asthenia
  • Edema
  • Arthralgia
  • Headache
  • Dizziness
  • Hypercholesterolemia
  • Sweating increased
  • Bone pain
  • Musculoskeletal

Not everyone experiences these side effects. There may be some side effects not listed above. If you have any concerns about a side-effect, please consult your doctor or pharmacist.



What drugs may interact with Femara® (letrozole)?

Femara® may interact with other drugs that you are currently taking, which can change how your drug works or increase your risk for serious side effects. To avoid any potential drug interactions, you should keep a list of all the drugs you are using (including prescription drugs, nonprescription drugs, and herbal products) and share it with your doctor and pharmacist. For your safety, do not start, stop, or change the dosage of any drugs without your doctor’s approval.

Some products that may interact with this drug include:

  • Estrogens (such as ethinyl estradiol, conjugated estrogens)
  • Estrogen blockers (such as anastrozole, tamoxifen)

Does food or alcohol interact with Femara® (letrozole)?

Femara® may interact with food or alcohol by altering the way the drug works or increase the risk for serious side effects. Please discuss with your doctor or pharmacist any potential food or alcohol interactions before using this drug.

What health conditions may interact with Femara® (letrozole)?

Femara® may interact with your health condition. This interaction may worsen your health condition or alter the way the drug works. It is important to always let your doctor and pharmacist know all the health conditions you currently have, such as:

  • High blood fats (cholesterol)
  • Bone problems (such as osteopenia, osteoporosis)
  • Stroke or blood clots
  • Heart disease (such as chest pain, heart attack, heart failure)
  • High blood pressure
  • Kidney problems
  • Liver problems



The information provided is not a substitute for any medical advice. You should ALWAYS consult with your doctor or pharmacist before using this medication.

What is the dose of Femara® (letrozole) for an adult?

Breast cancer

2.5 daily, until tumor progression evident.

Ovarian epithelial cancer (Off-label)

2.5 mg daily.

Other indications and uses including:

  • Adjuvant treatment of postmenopausal, hormone receptor positive, early breast cancer
  • Extended adjuvant treatment of early breast cancer in post-menopausal women after 5 years of adjuvant tamoxifen
  • First and second-line treatment of postmenopausal women with hormone receptor positive or unknown advanced breast cancer
  • Off-label: ovulation induction

What is the dose of Femara® (letrozole) for a child?

The dosage has not been established in pediatric patients. It may be unsafe for your child. It is always important to fully understand the safety of the drug before using. Please consult with your doctor or pharmacist for more information.

How is Femara® (letrozole) available?

Femara® is available in the following dosage forms and strengths:

  • Femara® tablets: 2.5 milligram letrozole

What should I do in case of an emergency or overdose?

In case of an emergency or an overdose, call your local emergency services or go to your nearest emergency room.

It is also important to carry a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking with you in case of emergencies.

What should I do if I miss a dose?

If you miss a dose of Femara®, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and take your regular dose as scheduled. Do not take a double dose.

Hello Health Group does not provide medical advice, diagnosis or treatment.

Review Date: December 29, 2016 | Last Modified: January 4, 2017

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