Entyvio (vedolizumab) is a prescription drug used to treat Crohn’s disease and ulcerative colitis (UC). As with other drugs, Entyvio can cause side effects, including a serious brain infection.

Entyvio works to reduce symptoms of Crohn’s disease or UC by decreasing inflammation. These conditions are autoimmune diseases, which means your immune system attacks your body and causes inflammation.

Entyvio comes as a solution that a healthcare professional injects into your vein over about 30 minutes. After the first two doses, you may continue to receive Entyvio as an infusion, or your doctor may have you switch to a subcutaneous injection (an injection under your skin). A healthcare professional can administer it, or you may self-inject the medication.

Entyvio is a biologic drug, which means it’s made from living cells. If this medication works for you, your doctor will likely recommend you use it long term.

Some people may have mild or serious side effects during Entyvio treatment. Examples of mild side effects that people receiving Entyvio have reported include:

Examples of mild side effects that have been reported with Entyvio include:

  • itchy skin and rash
  • joint pain
  • infections, such as a cold or respiratory infection
  • headache
  • nausea
  • fever
  • fatigue (lack of energy)
  • cough
  • back pain
  • mouth pain
  • pain in your arms or legs

To learn more about some of these side effects, see the “Side effects explained” section.

These side effects should mostly be temporary. And some may be easily manageable, too. But if you have any symptoms that are ongoing or bother you, talk with your doctor or pharmacist. And do not stop using Entyvio unless your doctor recommends it.

This list doesn’t include all side effects of Entyvio. See Entyvio’s prescribing information for details.

Serious side effects that people receiving Entyvio have reported include:

To learn more about some of these side effects, see the “Side effects explained” section.

If you develop serious side effects during Entyvio treatment, 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.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks and reviews side effects of the medication. Sharing your experience helps make medications safer for everyone by giving doctors and researchers more information about how the drug works in real life. If you develop a side effect while taking Entyvio and want to tell the FDA about it, visit MedWatch or call 800-FDA-1088.

Allergic reaction

For some people, Entyvio can cause an allergic reaction.

In general, symptoms of allergic reaction can be mild or serious.

What might help?

If you have mild symptoms of an allergic reaction, such as a mild rash, call your doctor right away. They may suggest a treatment to manage your symptoms and can determine whether you should keep using Entyvio.

If you have symptoms of a severe allergic reaction, such as swelling or trouble breathing, 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 Entyvio, they may have you switch to a different treatment.

Entyivo may cause long-term side effects, which may last even after you have stopped treatment.

Long-term side effects that people receiving Entyvio have reported include:

Get answers to some frequently asked questions about Entyvio’s side effects.

How long do Entyvio’s side effects last?

It varies. How long Entyvio’s side effects last depends on the types of side effects you’re experiencing. For example, an infection such as a cold or flu likely won’t be long term. But other side effects, such as liver problems or back pain, may last much longer.

Talk with your doctor about your risk of developing long-term side effects. They might monitor you for symptoms of side effects that could last for an extended period. As a result, your doctor may be able to treat these side effects earlier.

If you develop side effects that bother you, talk with your doctor. They can suggest ways to treat the side effects or recommend other medications to treat your condition.

Can Entyvio cause hair loss or weight gain?

No, Entyvio doesn’t typically cause hair loss or weight gain. People receiving Entyvio in studies did not report either of these side effects.

Other medications that can help treat ulcerative colitis (UC) or Crohn’s disease may cause hair loss or weight gain. For example, prednisone may be used to treat flare-ups of either of these conditions. This drug can cause both hair loss and weight gain.

If you notice hair loss or weight gain during Entyvio treatment, talk with your doctor. They can help determine the cause and recommend ways to decrease these side effects.

Is anxiety one of Entyvio’s side effects?

No, anxiety wasn’t a side effect reported in studies of Entyvio.

But it’s possible that you may develop anxiety relating to your Crohn’s disease or UC. According to the authors of a 2021 systematic review, evidence indicates there is a possible link between high anxiety levels and inflammatory bowel disease (IBD). Some people may experience increased anxiety levels during flare-ups of Crohn’s disease or UC.

If you experience anxiety during Entyvio treatment, talk with your doctor. They can help determine what may be causing it and the best way to treat it.

How do Entyvio’s side effects compare with the side effects of Humira?

Entyvio and Humira (adalimumab) help treat UC and Crohn’s disease. The drugs work differently in your body to treat these conditions. As a result, these medications have some side effects that are similar and some that are different.

Entyvio and Humira can cause mild side effects, such as:

  • infections
  • rash
  • headache
  • nausea
  • fever
  • back pain

In addition, Entyvio may also cause fatigue (lack of energy), cough, and mouth, arm, or leg pain.

Injection site reactions are common with Humira. These may include symptoms such as itching, pain, and swelling in the area around the injection.

Entyvio and Humira may also cause serious side effects, such as allergic reaction and liver problems.

Entyvio can cause progressive multifocal leukoencephalopathy (PML), which is a serious and possibly life threatening infection. While Humira doesn’t cause PML, other neurological (nerve-related) side effects can occur with this drug. An example is multiple sclerosis.

If you’re interested in learning more about how Entyvio compares with Humira, talk with your doctor. They can discuss which drug may be better for you based on your medical conditions and other medications you take.

Can Entyvio cause eye-related side effects?

Although uncommon, it’s possible for Entyvio to cause eye-related side effects.

Vision changes may be a sign of a serious condition called progressive multifocal leukoencephalopathy (PML). PML is a rare but serious infection in your brain that can cause blurry vision and loss of vision. It can also result in other serious side effects, such as weakness, changes in personality or memory, and confusion.

In addition, liver problems can occur with Entyvio. A symptom of liver disease is jaundice (yellowing of the whites of your eyes).

If you notice any eye-related side effects during Entyvio treatment, tell your doctor right away. They’ll likely do some tests to determine what’s causing your eye problems. Based on what they find out, they may be able to recommend ways to treat your eye-related side effects.

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

Progressive multifocal leukoencephalopathy, a serious brain infection

Although rare, it’s possible to develop progressive multifocal leukoencephalopathy (PML) from Entyvio. This condition is a serious, potentially life threatening infection that affects your brain.

Even though PML is rare, you should be aware of its possible symptoms, including:

If you develop symptoms of PML, let your doctor know right away.

What might help

Throughout your Entyvio treatment, your doctor will watch for symptoms of PML. If you develop any symptoms of this condition, go to the hospital or contact your doctor right away. They’ll offer treatment for PML and recommend that you stop receiving Entyvio.

If you have additional questions about the possibility of PML occurring from Entyvio, talk with your doctor.

Itchy skin and rash

Entyvio can cause itchy skin or a rash. These are common side effects of the drug.

What might help

If you develop itchy skin or a rash during Entyvio treatment, contact your doctor. A rash can be a sign of an allergic reaction or an infusion-related reaction, though this is rare.

Your doctor will determine if the rash is serious and whether it needs treatment. If it requires treatment, they can recommend a cream or medication to soothe your itchy skin or rash.

Joint pain

You may have joint pain from Entyvio. Joint pain was one of the most common side effects reported by people receiving Entyvio.

What might help

If you have joint pain during Entyvio treatment, tell your doctor. They may be able to recommend over-the-counter medications, such as Tylenol (acetaminophen), or other treatment options for this side effect.

If you’re concerned about developing joint pain from Entyvio, talk with your doctor or pharmacist.

Liver problems

Entyvio may cause liver problems. Some people who received this medication had increased liver enzymes, which may indicate liver damage. Although this side effect is rare, it can be very serious or even life threatening.

You should watch for symptoms of liver problems while you’re receiving Entyvio. If you develop any of these side effects, report them to your doctor right away. Symptoms of liver problems include:

  • jaundice (yellowing of the eyes or skin)
  • belly pain
  • nausea

What might help

If you develop any symptoms during Entyvio treatment, tell your doctor right away. They can order blood tests to determine whether there’s a problem with your liver. If there is, they’ll work with you to develop the best treatment plan for you. They may also recommend that you stop receiving Entyvio.

Keeping track of side effects

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

Your side effect notes can include things such as:

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

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

Before receiving Entyvio, discuss your health history with your doctor. Entyvio may not be right for you if you have certain medical conditions or other factors affecting your health. Be sure to talk with your doctor if any of the following apply to you:

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.