If you have prostate cancer, your doctor might suggest Xtandi (enzalutamide) as a treatment option. It’s a prescription drug used to treat prostate cancer in adult males* when:

  • surgery to remove prostate cancer or hormone treatment to lower testosterone levels hasn’t worked, or
  • prostate cancer has spread to other parts of the body (metastatic prostate cancer) and responds to medication or surgery to lower testosterone levels

Xtandi comes as capsules and tablets that you swallow. If you and your doctor determine that it’s safe and effective for you, you’ll likely take it long term.

For more information about Xtandi, including details about its uses, see this in-depth article on the drug.

Like other drugs, Xtandi can cause mild to serious side effects (also known as adverse effects). Keep reading to learn more.

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

Some people may experience mild to serious side effects during their Xtandi treatment.

Examples of Xtandi’s most commonly reported side effects in studies include:

* To learn more about this side effect, see the “Side effects explained” section below.

These are just a few of the more common side effects reported by people who took Xtandi. These are not all the side effects the drug may cause.

Mild side effects have been reported with Xtandi use. Examples include:

* To learn more about this side effect, see the “Side effects explained” section below.

In most cases, these side effects should be temporary. And some may be easily managed. But if you have symptoms that are ongoing or bother you, talk with your doctor or pharmacist. And do not stop taking Xtandi unless your doctor recommends it.

Xtandi may cause mild side effects other than those listed above. See the drug’s prescribing information for details.

Serious side effects aren’t common with Xtandi, but they can occur. If you develop serious side effects while taking this drug, call your doctor right away. If the side effects seem life threatening or you think you’re having a medical emergency, immediately call 911 or your local emergency number.

Serious side effects that have been reported with Xtandi include:

* To learn more about this side effect, see the “Side effects explained” section below.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks side effects of the medication. If you’d like to notify the FDA about a side effect you’ve had with Xtandi, visit MedWatch.

Below are answers to some frequently asked questions about Xtandi’s side effects.

Does the 40-mg strength of Xtandi cause different side effects than the 80-mg strength?

It’s not likely. Side effects that were reported in studies of the drug were based on a dosage of 160 milligrams (mg) taken once daily. This is the recommended dosage for prostate cancer.

A 2021 study of enzalutamide* showed that starting treatment at lower doses (between 40 mg and 120 mg) didn’t lower the risk of side effects in people taking this drug to treat castration-resistant prostate cancer. (This is when prostate cancer continues growing even after a person receives therapy to lower their testosterone levels.)

Xtandi is available in both 40-mg and 80-mg strengths. Your doctor may prescribe either a single strength or a combination of strengths to equal your total daily dose. They’ll prescribe the strength and dosage that works best for you based on your individual situation.

If you have questions about Xtandi’s side effects, speak with your doctor or pharmacist.

* This is the active ingredient in Xtandi. (An active ingredient is what makes a drug work.)

Will stopping Xtandi cause certain side effects?

It’s unlikely. This was not reported in studies of the drug. Whether you experience certain side effects of Xtandi depends on your individual situation. This includes your overall health, other drugs you take, and other factors. Your doctor will talk with you about possible side effects of Xtandi and what you can expect before you begin treatment.

Do not stop taking Xtandi on your own. If you’re concerned about certain side effects and want to stop taking this drug, talk with your doctor first.

In rare cases, people receiving certain hormone treatments for prostate cancer may experience antiandrogen withdrawal syndrome. This is when prostate-specific antigen (PSA)* levels drop after stopping antiandrogen drugs such as Xtandi. High PSA levels can be one indicator of prostate cancer risk.

A 2015 study found that a few patients experienced lower levels of PSA after stopping enzalutamide. This is a positive reaction that happens rarely. Scientists aren’t sure why it happens and are still learning about this effect.

* PSA is a protein made by the prostate gland.

Can Xtandi cause eye-related side effects?

Eye-related side effects are not common with this drug. But in rare cases, people taking Xtandi can develop a condition called posterior reversible encephalopathy syndrome (PRES). This side effect was not reported in Xtandi’s studies. But there have been reports of this condition after the drug became available for use. PRES is a serious brain disorder that can cause:

  • vision changes
  • blindness
  • serious brain-related side effects, including:
    • headache

If you experience sudden eye-related problems with Xtandi, call your doctor right away. They’ll determine whether you have PRES and will likely have you stop treatment with this drug.

For more information about this side effect, see the prescribing information for Xtandi or talk with your doctor.

If I use Lupron with Xtandi, will I experience different side effects?

It’s possible. Lupron (leuprolide acetate) is a kind of hormone treatment used to lower testosterone levels in people with prostate cancer. Lupron has some similar and some different side effects than Xtandi.

Taking both drugs may increase your risk of certain side effects, such as:

Side effects of Lupron itself that don’t occur with Xtandi include:

If your doctor prescribes Lupron with Xtandi, they’ll discuss the possible side effects of both drugs and what to expect with treatment.

Is nausea a side effect of Xtandi?

It can be. While not a common side effect in Xtandi studies, nausea did occur in some people during treatment. For most people, this side effect was temporary and went away as they continued taking the drug.

If you experience serious nausea that’s bothersome with this drug, talk with your doctor. They’ll discuss ways to manage this side effect and determine whether you should stop Xtandi treatment.

Learn more about some of the side effects Xtandi may cause.

Fatigue (low energy)

Fatigue was one of the most common side effects in Xtandi’s studies. But keep in mind that fatigue can also be a symptom of cancer. And Xtandi is used to treat prostate cancer.

What might help

If you experience symptoms of fatigue, such as low energy or tiredness, talk with your doctor. Depending on the severity of your condition, they’ll discuss options for you to consider.

For mild fatigue, they may suggest lifestyle changes such as:

  • eating a balanced diet
  • avoiding alcohol
  • managing stress
  • getting plenty of rest

If you have severe fatigue that interferes with your quality of life, they may have you stop Xtandi treatment.


Taking Xtandi can cause diarrhea. This is a common side effect of the drug. If diarrhea is severe, it can cause dehydration from extreme fluid loss.

Xtandi can also cause other digestive side effects, such as constipation and nausea.

What might help

For mild cases of diarrhea, your doctor may suggest:

  • taking an over-the-counter antidiarrheal medication, such as loperamide (Imodium)
  • drinking adequate fluids to avoid dehydration

But if you experience diarrhea that’s bothersome or serious, call your doctor. They’ll discuss the severity of your symptoms and your treatment options. In some cases, if diarrhea is severe, they may have you temporarily stop taking Xtandi until your symptoms improve.

If you have questions about this side effect of Xtandi, talk with your doctor or pharmacist.

Hot flashes

Xtandi can cause hot flashes. This is a common side effect the drug can cause because it lowers testosterone levels in the body. Signs include sudden, intense sensations of heat that aren’t related to hot weather.

Symptoms may include:

What might help

To ease mild symptoms, you can try:

  • avoiding triggers, such as:
    • spicy foods
    • alcohol
    • hot drinks
  • making lifestyle changes, such as:
    • eating a low fat diet
    • getting regular exercise
    • getting good quality sleep

If you have severe symptoms, call your doctor. They may discuss other treatment options with you.

If you have questions about the likelihood of hot flashes with Xtandi treatment, ask your doctor or pharmacist for more information.

Posterior reversible encephalopathy syndrome (PRES)

Xtandi can cause a serious brain condition called PRES, which occurs due to swelling in the brain. This side effect was not reported in studies of the drug. But it was reported by people taking Xtandi after the drug was approved for use.

Symptoms can include:

What might help

If you experience symptoms of PRES, such as a seizure or sudden headache with vision changes, call your doctor right away. They’ll order certain diagnostic tests to check for PRES. If you have this condition, they’ll likely have you stop taking Xtandi and discuss other treatments with you.

Severe allergic reaction

Xtandi can cause allergic reactions in some people. Allergic reactions may be mild or serious.

Symptoms of mild allergic reaction may include:

Symptoms of a severe allergic reaction reported in studies of Xtandi include:

  • swelling of the face or lip
  • swelling of the tongue or throat, which can make it hard to breathe

What might help

If you have symptoms of an allergic reaction, call your doctor. They’ll decide whether you should continue Xtandi treatment based on your reaction.

For mild cases, they may suggest an over-the-counter antihistamine product, such as Benadryl, to help ease symptoms.

But if you have a severe allergic reaction, such as trouble breathing or swelling of your face, tongue, or lip, call 911 or your local emergency number right away. These symptoms could be life threatening and require immediate medical care. If your doctor confirms you’ve had a serious allergic reaction to Xtandi, they may have you switch to a different treatment.

If you have questions about allergic reactions from Xtandi, talk with your doctor or pharmacist.

Keeping track of side effects

During your Xtandi treatment, consider taking notes on any side effects you’re having. You can then share this information with your doctor. This is especially helpful when you first start taking a new drug or using a combination of treatments.

Your side effect notes can include things such as:

  • what dose of the drug you were taking when you had the side effect
  • how soon you had the side effect after starting that dose
  • what your symptoms were
  • how your symptoms affected your daily activities
  • what other medications you were taking
  • any other information you feel is important

Keeping notes and sharing them with your doctor will help them learn more about how Xtandi affects you. They can then use this information to adjust your treatment plan if needed.

Xtandi may not be right for you if you have certain medical conditions. (This is known as a drug-condition interaction.) Talk with your doctor about your health history before starting this drug. Other factors may also affect whether Xtandi is a good treatment option for you. These are described below.

Heart disease. Xtandi can cause ischemic heart disease. This can increase your risk of serious heart-related conditions such as stroke or heart attack. If you have heart disease, tell your doctor. They’ll discuss whether treatment with Xtandi is appropriate for you.

Seizure disorder. In rare cases, Xtandi can cause seizure. Tell your doctor if you have a history of seizures. Because this can increase your risk of seizures with Xtandi, your doctor will likely not prescribe Xtandi for you. If you have a seizure during treatment with Xtandi, your doctor will probably have you stop taking the drug.

Allergic reaction. If you’ve had an allergic reaction to Xtandi or any of its ingredients, your doctor will likely not prescribe it for you. Ask them about other medications that might be better options.

Risk of falls and bone fractures. Xtandi can increase your risk of falls, which may lead to bone fractures. Tell your doctor if you have a history of falls or fractures. They may check your bone density before you start Xtandi to help determine whether it’s the right treatment for you. In some cases, they may prescribe medication to help prevent bone density loss.

Alcohol and Xtandi

It’s not known whether Xtandi interacts with alcohol. But both Xtandi and alcohol are broken down by your liver. So drinking too much could interfere with the level of Xtandi in your body. And a higher level of the drug could increase your risk of side effects from it.

If you plan to drink alcohol, ask your doctor how much is safe with Xtandi.

Pregnancy and breastfeeding while taking Xtandi

Xtandi is approved to treat prostate cancer in males.* It’s not known whether it’s safe to use in pregnant or breastfeeding females.* There is no information on Xtandi’s effects in pregnant females.

This drug may cause harm to an unborn fetus. Males taking Xtandi should use effective birth control, such as a condom, during sex with partners who can become pregnant. They should do this throughout Xtandi treatment and for 3 months after stopping the drug.

If you have questions about these risks, talk with your doctor or pharmacist.

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

Xtandi is used to treat some kinds of prostate cancer when surgery or other kinds of drugs to lower testosterone levels haven’t worked. The drug may cause mild to serious side effects. If you have questions about them, talk with your doctor or pharmacist.

A few questions you may want to consider asking include:

  • Does a higher dose of Xtandi increase my risk of side effects?
  • Will my dosage of Xtandi be lowered if I have certain side effects?
  • Will my risk of side effects increase if I take Xtandi with other drugs?

To learn more about Xtandi, see these articles:

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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.