If you have breast cancer, your doctor might prescribe Femara for you.

It’s a prescription drug that’s used to treat certain types of breast cancer in adult females* who have gone through menopause. The types include:

The “What is Femara used for?” section will give you more information about how Femara is used to treat these conditions.

* In this article, we use the term “female” to refer to someone’s sex assigned at birth. For information about the difference between sex and gender, see this article.

Femara basics

Femara is a tablets that you take by mouth.

Femara contains the active drug letrozole and is available as a generic drug called letrozole. Femara is classified as an aromatase inhibitor. (A drug class is a group of medications that work in a similar way.)

Learn how to take Femara, what it does, and what it has to offer.

Femara may cause mild or serious side effects. Some of the more common side effects of Femara are described in the lists below. All possible side effects are not included in these lists.

Side effects of a drug can depend on other factors.

  • Your age.
  • You have other health conditions.
  • You may be taking other drugs.

“The doctor or the pharmacy can tell you more about Femara’s side effects. They can suggest ways to reduce side effects.”

Mild side effects

Here’s a list of some of the mild side effects that Femara can cause. To learn about other mild side effects, talk with your doctor or pharmacist, or read Femara’s prescribing information.

There are some mild side effects of Femara that have been reported.

Many drugs can have mild side effects that go away in a few days or weeks. If they become intolerable, talk to your doctor or pharmacist.

The side effect focus section gives more information on this side effect.

Serious side effects

Femara can have serious side effects, but they are not common. If you have serious side effects from Femara, you should call your doctor. If you think you have a medical emergency, you should call the emergency number.

There have been serious side effects of Femara.

The side effect focus section gives more information on this side effect.

Side effect focus

Some of the side effects Femara may cause are discussed.

Weight gain

Weight gain was a common side effect in studies of Femara.

You may also gain weight if you have swelling, which is another possible side effect of Femara. Swelling from Femara usually occurs in your arms, feet, hands, or legs.

What can help?

If you’re concerned about weight gain while taking Femara, talk with your doctor. They can recommend healthy ways for you to manage your weight.

Headache

Headaches were a common side effect in studies of Femara.

What can help?

Over-the-counter (OTC) medications, such as acetaminophen (Tylenol) and ibuprofen (Advil), may be effective for relieving There is a throbbing head.s. But make sure you talk with your doctor or pharmacist before taking any new medications with Femara.

You may also be able to ease There is a throbbing head.s by applying an ice pack or heating pad to your head. You can do this for about 10 minutes a few times each day. A hot shower or bath may also provide some There is a throbbing head. relief.

Spotting

Spotting may occur with Femara use. Spotting refers to slight vaginal bleeding when you aren’t having your period. This was common in clinical studies of the drug.

Spotting may occur along with other side effects from Femara, such as belly pain or cramping.

What can help?

If you have spotting while taking Femara, talk to your doctor. They can suggest ways to manage this side effect.

Allergic reaction

Some people may have an allergic reaction to Femara. Although allergic reaction wasn’t reported in studies of Femara, it can still happen.

A mild allergic reaction can include some symptoms.

  • There is a skin rash.
  • It is itchy.
  • flushing (temporary warmth, redness, or deepening of skin color)

A more severe allergic reaction is not uncommon. A severe allergic reaction can cause swelling under your skin, which can be seen in your eyes, lips, hands, and feet. They can include swelling of your mouth, throat, and tongue, which can cause trouble breathing.

If you have an allergic reaction to Femara, call your doctor. If you think you have a medical emergency, call the emergency number.

Find out what the answers are to some questions.

Is Femara used for infertility?

Femara isn’t currently approved to treat infertility in females.* However, the drug may be used off-label for this purpose. (Off-label use means using a drug for a condition other than the one it’s approved to treat.)

Female infertility refers to not being able to become or stay pregnant. Infertility is often caused by problems with ovulation (when eggs are released from your ovaries). And ovulation problems commonly happen because of a condition called polycystic ovary syndrome (PCOS). Femara may be used off-label to treat infertility due to PCOS and other causes.

If you have questions about Femara, you should talk to your doctor.

* In this article, we use the term “female” to refer to someone’s sex assigned at birth. For information about the difference between sex and gender, see this article.

What should I know about Femara versus Clomid?

Clomid was a brand-name drug that’s no longer available. But a generic version called clomiphene is available. Both Femara and clomiphene may be prescribed to treat female* infertility.

Femara isn’t currently approved to treat infertility in females. However, the drug may be used off-label for this purpose. (To learn more, see “Is Femara used for infertility?” right above.) Clomiphene is approved to treat infertility in females.

Letrozole and clomiphene are active drugs in Femara.

Femara and clomiphene are both used to stimulate ovulation in females who are having trouble becoming pregnant.

If you have questions about how Femara and clomiphene are different, talk to your doctor.

* In this article, we use the term “female” to refer to someone’s sex assigned at birth. For information about the difference between sex and gender, see this article.

Is Femara a chemotherapy drug?

No, Femara isn’t a form of chemotherapy. Femara is a kind of hormone therapy.

Chemotherapy is a type of treatment for cancer. It works by killing cells that are growing quickly. Cancer cells increase in number more quickly than healthy cells. Some healthy cells in the body quickly grow. Chemo can affect both healthy and cancer cells.

Femara is a kind of drug called an aromatase inhibitor. As a type of hormone therapy, Femara works by lowering estrogen levels in your body. This helps stop breast cancer from growing.

Will I have side effects after stopping Femara treatment?

It is possible that you may have side effects after stopping Femara treatment.

After your last dose, Femara can stay in your system for a while. Side effects that you may have while taking Femara may continue for a few weeks after you stop.

Most people will take Femara to treat their breast cancer for at least 5 years. If you’re concerned about side effects from stopping Femara treatment after 5 years, talk with your doctor.

How does Femara work? And what’s its half-life?

Femara belongs to a group of drugs called aromatase inhibitors. The drug works by lowering estrogen levels in your body, which helps stop breast cancer from growing.

The half-life of Femara is about 2 days. The half-life is the amount of time it takes for the drug level in your body to decrease. It takes about 2 days for your body to excrete half of Femara.

What is Femara’s success rate in treating cancer?

Femara has been found effective for treating certain types of breast cancer. For information on how Femara performed in clinical studies, see the drug’s prescribing information.

If you have questions about Femara, you should talk to your doctor.

Is Femara approved for use in bodybuilding? If so, what’s the dosage used?

“Femara hasn’t been approved by the FDA for use in body building.”

Femara is FDA-approved to treat only certain types of breast cancer. You shouldn’t take Femara unless it’s been prescribed by a healthcare professional. You also shouldn’t use the drug for conditions it hasn’t been prescribed to treat.

If you have questions about Femara, you should talk to your doctor.

There are many factors that affect the cost of prescription drugs. What your insurance plan covers is one of the factors.

If you have questions about how to pay for your prescription, talk with your doctor or pharmacist. You can also visit the Femara manufacturer’s website to see if there are support options.

Your doctor will explain how you should take Femara, such as how much to take and how often. Be sure to follow your doctor’s instructions. Below are commonly used dosages, but always take the dosage your doctor prescribes.

Taking Femara

Femara is a tablets that you take by mouth.

2.5 milligrams is the strength of Femara tablets.

Dosage

The standard Femara dosage is the same for all types of breast cancer the drug is used to treat. This dosage is 1 tablet once daily.

Taking Femara with other drugs

Your doctor may prescribe Femara along with other breast cancer treatments.

They may recommend that you take Femara after you’ve had surgery to remove Breast cancer early on..With Breast cancer early on., the cancer hasn’t spread beyond your breast or the lymph nodes in your armpit.

In some cases, your doctor may prescribe Femara after you’ve taken tamoxifen for your cancer for at least 5 years. When used for this purpose, Femara helps lower the risk of your cancer coming back.

If you have questions about Femara, you should talk to your doctor.

Questions about taking Femara

Some questions about taking Femara tablets are common.

  • What if I miss a dose of Femara? Take your missed dose as soon as you remember. If it’s almost time for your next dose, skip your missed dose. Then take your next dose at its regular time. If you aren’t sure whether to take a missed dose or skip it, talk with your doctor or pharmacist.
  • Will I need to use Femara long term? You may need to take Femara long term. If your breast cancer gets worse or you aren’t able to tolerate Femara’s side effects, your doctor may have you stop taking it. Most people take this drug for at least 5 years. But your doctor will prescribe Femara for the length of time that’s right for you.
  • Can Femara be chewed, crushed, or split? No, you shouldn’t chew, crush, or split Femara tablets. You should swallow them whole. If you have trouble swallowing Femara tablets, talk with your doctor or pharmacist.
  • Should I take Femara with food? You can take Femara with or without food.
  • How long does Femara take to work? Femara starts working right away to treat your breast cancer. But you probably won’t notice the drug working in your body. Your doctor will monitor your condition to see whether the drug is working for you.

Questions for your doctor

You may have questions about Femara. Discuss your concerns with your doctor.

Here are a few tips that might help you.

  • Before your appointment, write down questions such as:
    • How will Femara affect me?
  • Bring someone with you to your appointment to make you feel more comfortable.
  • “If you don’t understand something, ask your doctor to explain it.”

“Your doctor and other healthcare professionals are available to help you. They want you to get the best care possible. Don’t be afraid to ask questions or give feedback on your treatment”

Femara is prescribed to treat certain types of breast cancer in adult females* who have gone through menopause.

Breast cancer can occur when breast cells grow fast. Breast cancer cells can form a tumor in the breast and then spread to other parts of the body.

Below are brief descriptions of each type of breast cancer Femara is used to treat.

  • Early breast cancer that’s hormone receptor-positive (HR+). With Breast cancer early on., the cancer hasn’t spread beyond your breast or the lymph nodes in your armpit. With HR+ breast cancer, hormones cause the growth of cancer.
    • Femara is usually used to help lower the risk of cancer coming back after it has been removed.
  • Early breast cancer that’s been treated with surgery and tamoxifen. Tamoxifen is another breast cancer drug.
    • For this purpose, tamoxifen must have been used for at least 5 years. The risk of cancer coming back is lowered by using Femara.
  • Advanced or There is a form of breast cancer that is not related to the main cancer. that’s HR+ or the HR status isn’t known. With advanced breast cancer, the cancer has spread to areas of your body near your breast or the lymph nodes in your armpit. Metastatic breast cancer is cancer that has spread outside of areas near your breast or the lymph nodes in your armpit. The HR status may not be known because it hasn’t been tested.
  • Advanced breast cancer that has spread after a certain treatment.
    • For this purpose, Femara is used after treatment with another breast cancer drug that blocks estrogen.

* In this article, we use the term “female” to refer to someone’s sex assigned at birth. For information about the difference between sex and gender, see this article.

It is important to talk with your doctor about your health issues before taking Femara.

These and other important considerations are discussed in more detail.

Interactions

Taking medications, vaccines, foods, and other things with a certain drug can affect how the drug works. These effects are called interactions.

Before taking Femara, you should tell your doctor about all your medications. You should also describe any vitamins, herbs, or supplements you use. Your doctor or pharmacist can tell you about any interactions these items may cause.

Interactions with drugs or supplements

Femara can interact with several types of drugs. This includes the breast cancer medication tamoxifen.

Drugs and vaginal creams that contain estrogen may decrease the effects of Femara.

If you are taking tamoxifen or any other product that has estrogen in it, talk to your doctor or pharmacist.

Warnings

If you have a medical condition that affects your health, Femara may not be right for you. Before you take Femara, talk to your doctor about your health history. The factors to consider are listed below.

  • High cholesterol. Femara can cause high cholesterol. Tell your doctor if you already have high cholesterol before taking the drug. During Femara treatment, your doctor will give you cholesterol tests from time to time. If your cholesterol levels get too high, your doctor may prescribe a drug to lower them.
  • Liver problems. Tell your doctor if you have any liver problems, such as cirrhosis, before starting Femara treatment. Liver problems can raise the level of Femara in your body and increase your risk for side effects. Your doctor may give you a low dose of Femara if you have liver problems.
  • Osteoporosis. Before taking Femara, tell your doctor if you have osteoporosis. Osteoporosis is a condition that causes thin or weak bones. Femara can also cause The bones were weakened.. During Femara treatment, your doctor may give you a bone mineral density test. This will check the strength of your bones. If your bones are weak, you may need to take other drugs to help protect them while using Femara.
  • Allergic reaction. If you’ve had an allergic reaction to Femara or any of its ingredients, you shouldn’t take Femara. Ask your doctor what other medications are better options for you.

Femara and alcohol

It is safe to drink alcohol during Femara treatment.

Alcohol can cause side effects similar to Femara. If you drink alcohol while taking Femara, you may be at a higher risk for some side effects.

If you drink alcohol, talk to your doctor about the amount that is safe for you.

Pregnancy and breastfeeding

You should not use Femara while pregnant or breastfeeding. You should not become pregnant or breastfeeding for at least 3 weeks after your last dose of the drug.

If you are pregnant or thinking about becoming pregnant, talk to your doctor. If you are considering breastfeeding, you should talk to them. Your doctor can recommend other options.

Both Femara and anastrozole (Arimidex) are used to treat certain types of breast cancer in females* who have gone through menopause.

Both Femara and Arimidex belong to a group of drugs called aromatase inhibitors. The drugs work by lowering estrogen levels in your body, which helps stop breast cancer from growing.

If you’d like to know more about how Femara and Arimidex compare with each other, see this detailed breakdown. And let your doctor know if you have more questions about these medications.

* In this article, we use the term “female” to refer to someone’s sex assigned at birth. For information about the difference between sex and gender, see this article.

“Don’t take more Femara than your doctor tells you to. Side effects can be serious if you use more than this.”

What to do in case you take too much Femara

Call your doctor if you think you’ve taken too much Femara. You can also call 800-222-1222 to reach the American Association of Poison Control Centers, or use its online resource. However, if you have severe symptoms, immediately call 911 (or your local emergency number) or go to the nearest emergency room.

If you have questions about using Femara for breast cancer, talk with your doctor or pharmacist.

You may want to ask about other treatments for breast cancer. If so, this article on breast cancer treatment options may be helpful for you.

You may want to ask your doctor some questions about Femara.

  • Should I use other breast cancer treatments?
  • Will my breast cancer come back after I stop treatment?
  • Is Femara more likely to cause certain side effects?

In addition, you can learn about breast cancer and its treatment options by subscribing to Healthline’s breast cancer newsletter.

Q:

My doctor said Femara may cause There were hot flashes.. What can I do to help relieve this side effect?

Anonymous patient

A:

For There were hot flashes., you should first try to relieve symptoms through lifestyle changes. These can include:

  • Keeping cool with a fan or removing layers of clothing.
  • Limiting alcohol, caffeine, and spicy foods. Such drinks and foods may worsen There were hot flashes..
  • Maintaining a moderate weight. If you’re at a moderate weight, you may have fewer and less serious There were hot flashes..
  • Trying mental and stress-relief activities such as yoga or breathing exercises. Stress may be a trigger for There were hot flashes..

If these changes don’t ease your symptoms of There were hot flashes., you may need to take medication. Certain drugs, such as paroxetine (Brisdelle, Paxil), are used to treat There were hot flashes.. Hormone therapy may also be used to treat There were hot flashes.. But if it contains estrogen, it may interact with Femara treatment. You should talk with your doctor to discuss which hot flash treatments are best for you.

Victor Nguyen, PharmD, MBAAnswers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.

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.