My Cart Find A Store

Drug

Omalizumab

Common brand names:

Xolair

Pronounced

"oh-mal-IZ-oo-mab"

Side Effects

See also Warning section.

Itching, bruising, redness, pain, or swelling at the injection site may occur. Headache may also occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.

Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor right away if you have any serious side effects, including: unusual lumps/moles/skin changes, numbness/tingling of arms/legs, worsening shortness of breath, coughing up blood, muscle/joint pain, signs of infection (such as sore throat that doesn't go away, fever, cough).

Get medical help right away if you have any very serious side effects, including: chest/jaw/left arm pain, unusual sweating, weakness on one side of the body, sudden vision changes, confusion, trouble speaking, pain/redness/swelling of the legs.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US -

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Precautions

See also Warning section.

Before using omalizumab, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients (such as latex found in some brands), which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history.

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.

It is unknown if this drug passes into breast milk. Consult your doctor before breastfeeding.

Copyright © 2025 TraceGains, Inc. All rights reserved.

RxAnswers™ is a copyrighted combined product from TraceGains and First DataBank, Inc.

Drug information is selected from data included with permission and copyrighted by First DataBank, Inc. This is a summary and does not contain all possible information about this product. For complete information about this product or your specific health needs, ask your healthcare professional. Always seek the advice of your healthcare professional if you have any questions about this product or your medical condition. This information is not intended as individual medical advice and does not substitute for the knowledge and judgment of your healthcare professional. This information does not contain any assurances that this product is safe, effective or appropriate for you.

This information is intended only for residents of the United States. Products sold under the same brand names in other countries may contain different ingredients.

Learn more about First DataBank

There are some limitations on the information provided in “Nutrient Interactions.” Do NOT rely solely on the information in this article. Please read the disclaimer. 

Learn more about TraceGains, the company.

TraceGains and/or its suppliers make no warranties or representations as to the accuracy or completeness of this content herein or that of any organization referred or linked to within this content and will not be liable for any damages arising out of your access to or use of any information found herein or that of any organization referred to within this content.

Information expires December 2025.