TREATMENT GUIDE
Omalizumab (Xolair®) for food allergy
FDA-approved February 2024
An injection every two to four weeks
Protection stops when injections stop
Reviewed by Hunter Smith, MD · Last reviewed October 2026
IN SHORT
Omalizumab, sold as Xolair®, is an injection given every two to four weeks. The FDA approved it in February 2024 to reduce allergic reactions to foods in people aged 1 and older.
It is the only FDA-approved treatment for food allergy in the United States.
Xolair® works differently from immunotherapy. It blocks the antibody that drives allergic reactions, instead of retraining the immune system. You do not eat the food as part of treatment.
Because it does not retrain the immune system, protection stops when the injections stop.
In the trial that led to approval, about 67 in 100 people could tolerate 600 mg of peanut protein (roughly two and a half peanuts) while on treatment, compared with about 7 in 100 on placebo.
Xolair® does not make foods safe to eat freely. It is meant to reduce the severity of an accidental exposure.
How Xolair® works
The antibody behind reactions
Allergic reactions to food are driven by an antibody called IgE. Omalizumab binds to IgE and stops it from triggering the cells that cause allergic reactions. Because it acts on IgE in general, it works across several foods at once.
Why protection stops
Immunotherapy tries to change how your immune system responds to a food, ideally by making fewer IgE antibodies over time, so protection may last. Omalizumab binds the IgE antibodies that already exist, but it does not stop the body from making more. Once the drug wears off, protection stops.
How well Xolair® works
67 vs 7
in 100 could tolerate 600 mg of peanut protein
About 67 in 100 people on Xolair® (about 2.5 peanuts) compared with about 7 in 100 on placebo.
7 foods
it worked across seven different foods
Including peanut, tree nuts, milk, egg, and wheat.
14 in 100
could not tolerate even small amounts of peanut
Xolair® does not work for everyone.
The main trial
The main trial for FDA approval enrolled 180 people with peanut allergy plus at least two other food allergies. Almost all were 17 or younger. They took omalizumab or a placebo for about four months, to give the drug time to bind to existing IgE antibodies.
More than one food
About 69 in 100 people tolerated a set amount of two foods, and 47 in 100 tolerated three. It is not known why Xolair® worked better for some foods than others.
Responses varied a lot from person to person.
About 14 in 100 people could not tolerate even small amounts of peanut after treatment. Xolair® does not work for everyone.
Compared with treating several foods by OIT
Xolair® has also been tested against oral immunotherapy for treating several foods at once, in a trial of 117 people with a median age of 7. In this study, all people received 16 weeks of omalizumab® to start. After 8 weeks of omalizumab® multi-food OIT participants started OIT and escalated to goal doses. At 16 weeks, the multi-food OIT group stopped receiving omalizumab®.
Topic
OMALIZUMAB
MULTI-FOOD OIT
Met the main goal
36 in 100
19 in 100
Stopped before the end
12 in 100
49 in 100
Serious side effects
None
31 in 100
Needed epinephrine
7 in 100
37 in 100
Met the main goal
Omalizumab
36 in 100
Multi-food OIT
19 in 100
Stopped before the end
Omalizumab
12 in 100
Multi-food OIT
49 in 100
Serious side effects
Omalizumab
None
Multi-food OIT
31 in 100
Needed epinephrine
Omalizumab
7 in 100
Multi-food OIT
37 in 100
An important note on effectiveness: when researchers looked only at people who finished both treatments, the gap narrowed. Much of Xolair®’s advantage came from the fact that more people were able to stay on it.
What to know before starting
It is an injection every two to four weeks, depending on your total IgE and weight, given indefinitely.
Injections may be done at home after initial training in the clinic.
Insurance may cover it, since it is FDA-approved.
You may need prior authorization first, and the cost still ranges from $5 to $1,475 a month.
You still need to avoid the food and carry epinephrine.
Xolair® reduces the severity of an accidental exposure. It does not make the food safe to eat.
It can be used alongside immunotherapy, not just instead of it.
Some allergists use it to make the early, harder part of oral immunotherapy easier to get through.
A reaction to the injection itself is rare, but possible.
This is why your first few doses are given under supervision at the clinic.
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