Omalizumab: What It Is, How It Works, and What You Need to Know

When your asthma won’t respond to inhalers, omalizumab, a monoclonal antibody that targets immunoglobulin E (IgE) to reduce allergic reactions. Also known as Xolair, it’s not a rescue inhaler—it’s a long-term shield for people whose asthma is driven by allergies. Unlike steroids or bronchodilators, omalizumab doesn’t open airways. Instead, it stops the allergic cascade before it starts by binding to IgE, the antibody that triggers histamine release and inflammation in allergic asthma.

This treatment is for adults and kids over 6 with moderate to severe persistent asthma that’s clearly tied to allergies. If you’ve tried high-dose inhaled corticosteroids and long-acting beta-agonists but still wheeze, cough, or wake up at night, omalizumab might be the next step. It’s given as a subcutaneous injection every 2 to 4 weeks, usually at a doctor’s office. You won’t feel it working right away—it takes weeks for IgE levels to drop and symptoms to improve. But for many, it means fewer ER visits, less reliance on oral steroids, and the ability to breathe through allergy season without panic.

Omalizumab doesn’t work for everyone. It’s not for non-allergic asthma, COPD, or sudden asthma attacks. It also carries a small risk of anaphylaxis—usually within the first few doses—which is why you’re monitored for at least 2 hours after each injection. Still, for those who respond, it’s life-changing. Patients often report being able to keep pets, go outside in spring, or stop carrying an EpiPen because their allergic triggers no longer trigger asthma flares.

The posts below cover real-world concerns tied to omalizumab and similar therapies: how to manage side effects like headaches or fatigue, what to do if you miss a dose, how it interacts with other meds, and why some people stop taking it even when it works. You’ll also find guides on monitoring asthma control, recognizing allergic triggers, and understanding biologic treatments like omalizumab compared to newer options. Whether you’re just starting this treatment or have been on it for years, these resources help you ask better questions, track progress, and stay safe.