Xolair’s Side Effects: What to Know

Medically Reviewed By Heather Bruce, PharmD
Xolair has a boxed warning for risk of a severe allergic reaction called anaphylaxis. This is a serious warning from the Food and Drug Administration (FDA). For details, see the “ Xolair: Side effects explained” section below.

Xolair: Introduction

Xolair is a brand-name prescription drug. It’s a type of drug called a monoclonal antibody, which is a biologic drug. (Biologic drugs are made from living cells.)

This medication contains the active drug omalizumab. It comes as a solution as well as a powder that’s mixed with liquid to form a solution. Xolair is given as a subcutaneous injection.

Xolair is approved by the Food and Drug Administration (FDA) for use in specific situations to treat:

  • a certain type of hives called chronic spontaneous urticaria in adults and children ages 12 years and older
  • specific types of asthma in adults and children ages 6 years and older
  • nasal polyps in certain adults

Similar to other drugs, Xolair may cause side effects or complications. Read below for information about possible side effects of this injection (shot), including common, mild, and serious ones.

For a general overview of Xolair, including details about its uses, see this article.

If you’d like to use Xolair, search here to find a healthcare professional who might prescribe it.

Xolair: More common side effects

Some of Xolair’s side effects may be more common than others. These side effects may last only a few days to weeks. However, some side effects may last longer or become severe or bothersome. Tell your doctor or pharmacist if you have concerns about any side effects with Xolair.

Some of the more common side effects of Xolair in adults that occurred during clinical studies are listed below. These side effects can vary depending on the condition Xolair is being used to treat.

Xolair is also prescribed for certain children with hives and asthma. For more information about side effects in children using the drug, see the “Xolair: Side effects in children” section below.

More common side effects of Xolair in adults with a certain type of hives called chronic spontaneous urticaria include:

More common side effects of Xolair in adults with a certain type of asthma include:

More common side effects of Xolair in adults with nasal polyps include:

* For more information about this side effect, see “Xolair: Side effects explained” below.

Xolair: Mild side effects

Xolair can cause mild side effects, which are listed below. However, this list doesn’t include all possible mild side effects. To learn more about Xolair’s side effects, view the drug’s prescribing information.

Xolair’s mild side effects include:

The side effects listed above may last only a few days to weeks. However, some side effects may last longer or become severe or bothersome. Tell your doctor or pharmacist if you have concerns about side effects with Xolair.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks side effects of the medication. If you develop a side effect while using Xolair and want to tell the FDA about it, visit MedWatch.

* For more information about this side effect, see “Xolair: Side effects explained” below.

Xolair: Serious side effects

It’s possible to have serious side effects with Xolair. Serious side effects are listed below, but this list may not include all possibilities. To learn more about Xolair’s side effects, view the drug’s prescribing information.

Call your doctor right away if you have serious side effects with Xolair. However, if you think you’re having a medical emergency or life threatening side effects, call 911 or your local emergency number.

Serious side effects of Xolair and their possible symptoms include:

* For more information about this side effect, see “Xolair: Side effects explained” below.
Xolair has a boxed warning for this side effect. This is the most serious warning from the Food and Drug Administration (FDA). To learn more, see the “Xolair: Side effects explained” section below.

Xolair: Side effects in children

Xolair is approved to treat a certain type of hives called chronic spontaneous urticaria in children ages 12 years and older. It is also approved to treat specific types of asthma in children ages 6 years and older.

Many side effects of Xolair are expected to be the same in children and adults. For lists of the drug’s possible side effects, see the “Xolair: Mild side effects” and “Xolair: Serious side effects” sections above.

That said, certain side effects of Xolair may be more common in children than in adults.

Side effects in children who used Xolair to treat hives were similar to side effects in adults. However, there were side effects that were more common in children ages 6 to 12 years with asthma than in adults. Examples include:

Children who used Xolair for asthma occasionally had to stop using the drug. This was because they developed hives or bronchitis.

If you have questions about how Xolair may affect your child, talk with their doctor or pharmacist.

Xolair: Common questions about side effects

Here are some common questions about the drug’s side effects and answers to them. Talk with your doctor if you have other questions about this drug.

Does Xolair cause weight gain or weight loss as a side effect?

No. Weight gain and weight loss weren’t reported by people using Xolair in clinical studies.

If you have questions about weight changes, talk with your doctor. They can recommend ways to maintain a body weight that’s healthy for you while you’re using this drug.

Are there long-term side effects of Xolair?

It’s possible that Xolair may cause long-term side effects. However, they were rare in clinical studies. Long-term side effects are ones that happen after you’ve taken the drug for a long time. Or they could be side effects that continue after you’ve stopped treatment.

Possible long-term side effects of Xolair include:

Xolair also has a boxed warning for a severe allergic reaction called anaphylaxis. This is a serious warning from the Food and Drug Administration (FDA). This side effect could happen at the beginning of treatment or after you’ve been using Xolair for a long time.

For details about cancer or anaphylaxis with Xolair, see the “Xolair: Side effects explained” section below.

If you are concerned about long-term side effects of Xolair, talk with your doctor or pharmacist.

Will I have withdrawal symptoms as side effects if I stop using Xolair?

No. Clinical studies of Xolair did not report withdrawal symptoms as a side effect. (Withdrawal symptoms are side effects that can happen after you stop taking a drug that your body is dependent on. With dependence, your body needs the drug in order to function like usual.)

However, if you stop using Xolair, you may begin to experience symptoms of your condition again. If you have questions about stopping treatment with Xolair, be sure to talk with your doctor.

Is depression a possible side effect of Xolair?

No. Depression was not reported as a side effect of Xolair in clinical studies.

However, some people who used Xolair experienced fatigue or pain. And these are possible symptoms of depression.

Also, anxiety was a rare side effect of Xolair in clinical studies. And anxiety may be linked with depression.

If you have questions about certain side effects of Xolair, talk with your doctor or pharmacist.

Does Xolair cause side effects related to immunosuppression? Is it an immunosuppressant drug?

Yes, Xolair can cause side effects related to immunosuppression. And it is an immunosuppressant drug.

Xolair works with your immune system to block an antibody (immune system protein) called immunoglobulin E (IgE). High levels of this antibody can cause inflammation. So, by blocking IgE, Xolair can decrease inflammation.

Immunosuppressant drugs, such as Xolair, can also decrease your immune system’s ability to fight off infections. With Xolair, you may be more likely to develop a parasitic infection. This is because IgE typically fights off parasites.

Some people who took Xolair in clinical studies developed the following types of infections:

However, severe infections were not as common. Xolair may not suppress your immune system as much as other immunosuppressant drugs, such as corticosteroids.

Xolair: Side effects explained

Here’s detailed information about some of Xolair’s side effects.

Allergic reaction and risk of a severe allergic reaction called anaphylaxis

As with most drugs, some people can have an allergic reaction after injecting Xolair. A more severe allergic reaction is rare but possible.

In fact, Xolair has a boxed warning for the risk of a severe allergic reaction called anaphylaxis. A boxed warning is the most serious warning from the Food and Drug Administration (FDA). Anaphylaxis is a severe allergic reaction, and it was a rare side effect in Xolair’s clinical studies. It’s a medical emergency and can lead to death if not treated right away.

Anaphylaxis has been reported at the beginning of Xolair treatment. It has also been reported after someone had used Xolair for a year. In these cases, anaphylaxis happened about 2 hours after injecting a dose of Xolair. However, that does not mean this will be the timing of all cases of anaphylaxis.

Possible symptoms of mild and serious allergic reactions are listed in the table below.

Mild allergic reaction symptoms Serious allergic reaction or anaphylaxis symptoms
• itching trouble breathing
rash • swelling in your throat or mouth
flushing • swelling under your skin, possibly in your hands, feet, lips, or eyelids

What to do

If you have an allergic reaction to Xolair, call your doctor right away. This is important to do because the reaction could become severe.

However, if you’re having a medical emergency or your symptoms feel life threatening, call 911 or a local emergency number.

Hair loss

Hair loss is a possible side effect of Xolair. However, it was not a commonly reported side effect in clinical studies.

Hair loss can vary in severity. If you have hair loss, you may see:

  • a receding hairline
  • bald spots
  • more hair than usual in your shower drain

What to do

If you are experiencing hair loss, talk with your doctor. They may be able to recommend medications to help treat hair loss. Examples include a prescription drug called finasteride (Propecia) and an over-the-counter drug called minoxidil (Rogaine).

If your hair loss with Xolair is bothersome, your doctor may also switch you to a different medication.

Cancer

In rare cases, certain types of cancer were reported in clinical studies of Xolair. These types of cancer include:

Symptoms of cancer can vary but may include changes in appetite, changes in bowel or bladder function, or extreme fatigue. Other symptoms may include abnormal lumps or swelling in the body, persistent cough, or abnormal bleeding or bruising.

It’s unclear whether Xolair caused these instances of cancer. Other risk factors, such as smoking and age, may have also played a role.

What to do

It’s important to keep up with the recommended cancer screening for your age group. This may include pap smears, mammograms, or colonoscopies.

If you notice unusual changes or growths on your skin, talk with your doctor. Learn more about how to recognize different types of skin cancer in this article.

Before starting Xolair, talk with your doctor about your risk of developing certain cancers.

Fatigue

Fatigue may occur with Xolair. It was a common side effect in clinical studies involving people with asthma. Fatigue can be mild, moderate, or severe.

Symptoms of fatigue may include:

Other medical conditions, such as anemia and depression, can also cause fatigue.

What to do

If you are experiencing fatigue with Xolair, talk with your doctor about ways to manage it. There are several lifestyle changes that may help with fatigue. Some of these include:

  • following a healthy diet
  • practicing good sleep hygiene
  • getting more exercise
  • drinking plenty of fluids
  • limiting alcohol consumption
  • trying stress-relieving activities, such as yoga

Be sure to tell your doctor about your medical history and any medications you take. Doing so will help your doctor find the best treatment option for you.

Headache

Headache is a possible side effect of Xolair. In clinical studies, it was a common side effect in people with nasal polyps and a certain type of hives called chronic spontaneous urticaria.

A headache may include discomfort in your head, neck, eyes, or forehead. Symptoms may start gradually or come on very quickly. Some possible symptoms of headache are:

  • throbbing pain
  • pulsing pain
  • pressure
  • tenderness
  • trouble sleeping
  • sensitivity to light

Headache symptoms can be mild to severe. They can last a short time or a long time. And they may get worse when you do physical activities, such as jogging or carrying heavy things.

What to do

Some headaches from Xolair may go away once your body gets used to the drug. However, if you have a headache that is severe or long lasting, talk with your doctor. They may suggest an over-the-counter pain reliever such as acetaminophen (Tylenol), ibuprofen (Motrin), or naproxen (Aleve).

There are also strategies other than medication that may help reduce your discomfort. These include:

  • making changes in your diet, such as reducing sodium intake
  • sitting in a quiet, dark room
  • drinking plenty of fluids
  • getting enough sleep
  • trying acupuncture therapy

If you are experiencing headaches with Xolair, talk with your doctor about what treatment plan is best for you.

Xolair: Precautions

Xolair has several warnings.

Boxed warning: Risk of severe allergic reaction called anaphylaxis

This drug has a boxed warning for a severe allergic reaction called anaphylaxis. This is a serious warning from the Food and Drug Administration (FDA). For details, see the “Xolair: Side effects explained” section above.

Other precautions

Be sure to talk with your doctor about your health history before you start Xolair treatment. This drug may not be the right treatment option for you if you have certain medical conditions or other factors that affect your health.

The conditions and factors to consider include those described below.

History of cancer. If you’ve had cancer in the past, your risk of getting cancer again may be higher with Xolair. Talk with your doctor about your medical history and the risks and benefits of using Xolair.

Latex allergy. If you have an allergy to latex or rubber, you may have a reaction to the needle cap on Xolair prefilled syringes. Talk with your doctor about whether a different form of Xolair is safe for you to use.

Parasitic infection. Xolair decreases your immune system’s ability to fight off some infections. This is especially true for parasitic infections. If you had or have a parasitic infection, talk with your doctor about whether Xolair is right for you. They may choose a different medication for you.

Sudden breathing problems. If you have a symptom of asthma called bronchospasm, Xolair may not be safe for you. (With bronchospasm, your lungs contract and make it hard for you to breathe.) Talk with your doctor about the risks and benefits of Xolair for asthma. Since Xolair is not used to treat sudden breathing problems, your doctor may prescribe an asthma rescue medication. An example of this medication is albuterol (Proair HFA, Proventil HFA, Ventolin HFA). Your doctor may also decide not to prescribe Xolair for you.

Allergic reaction or history of anaphylaxis. Anaphylaxis is a serious allergic reaction that can lead to death. If you’ve had anaphylaxis or an allergic reaction to Xolair before, this drug is contraindicated. (A contraindication is a factor or condition that could prevent your doctor from prescribing a drug due to risk of harm.) In this case, your doctor will likely not prescribe Xolair due to risk of death. Ask your doctor what other medications may be better options for you. (For more details, see the “Boxed warning: Risk of severe allergic reaction called anaphylaxis” section above.)

Consuming alcohol during Xolair treatment

There aren’t any known interactions between Xolair and alcohol. However, it may be best to avoid alcohol while using this drug.

Alcohol may worsen some conditions that Xolair treats. For example, alcohol can worsen symptoms of nasal polyps, such as sinus congestion, sinus pain, or sinus pressure.

Xolair and alcohol both decrease immune system function. So, if you consume alcohol and use Xolair, your immune system function may be further decreased. And this can increase your risk of infection.

If you drink alcohol, talk with your doctor about the amount that is safe for you while using Xolair.

Pregnancy and breastfeeding during Xolair treatment

It is unknown whether Xolair has an effect on pregnancy or breastfeeding.

In clinical studies, there were reports of low birth weight in infants born to people who took Xolair while pregnant. However, the exact cause of this effect is unknown, since the people in the studies had more severe asthma.

If you are pregnant or planning a pregnancy, talk with your doctor. They can help you weigh the benefits and risks of treatment with Xolair while pregnant.

There is not enough information in clinical studies of Xolair to know if it passes into breast milk.

If you’re breastfeeding or planning to do so, talk with your doctor. They can recommend healthy ways to feed your child while using Xolair.

Xolair: What to discuss with your doctor

Talk with your doctor or pharmacist to find out more about Xolair. If you have questions about the drug’s side effects, your pharmacist or healthcare professional can help answer them for you.

Most side effects that you have with Xolair are mild and usually go away. You can talk with your doctor about how to watch out for some of the more serious side effects, such as anaphylaxis, cancer, and bone fracture.

In addition to discussing Xolair with your doctor, you may find the following articles helpful in learning more.

  • Overview of Xolair. To read an overview of Xolair, see this article.
  • Drug comparison. To learn how Xolair compares with Dupixent, read this article
  • Details about asthma. To learn more about asthma, which Xolair is used to treat, see this asthma article.
  • A look at nasal polyps. For more information about nasal polyps, refer to this article.
  • A look at chronic spontaneous urticaria. For more information about hives, including chronic spontaneous urticaria, refer to this article.

Disclaimer: Healthgrades 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.

Medical Reviewer: Heather Bruce, PharmD
Last Review Date: 2022 Apr 24
THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.