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Does Xolair cause hair loss?

Medically reviewed by Leigh Ann Anderson, PharmD. Last updated on Feb 21, 2024.

Official answer


Hair loss (alopecia) has been reported in Xolair clinical studies in at least 2% of people with chronic hives. Hair loss has also been noted in several case reports with Xolair. The hair loss effect appears to be transient, lasting from 3 to 4 months. Due to limited data, the exact cause of hair loss or how often it occurs is not known.

  • The manufacturer reported hair loss (alopecia) in at least 2% of 427 patients receiving 150 mg or 300 mg of Xolair (omalizumab) in two 24-week long chronic hives (chronic spontaneous urticaria) clinical studies.
  • Hair loss with Xolair treatment occurred more frequently than in those receiving a placebo (a treatment with no active medicine).

Xolair is approved to treat asthma triggered by allergies, nasal polyps chronic hives (also called chronic spontaneous urticaria) and to help reduce serious allergic reactions due to accidental exposure to certain foods (along with avoiding foods to which you are allergic). It is not used for the emergency treatment of allergic reactions, including anaphylaxis.

Xolair is a subcutaneous (under the skin) injection and is typically used when other treatments have not been effective to control your symptoms. It works by inhibiting the binding of the IgE antibody (or immunoglobulin) to IgE receptors on mast cells and basophils.

Is alopecia reported with Xolair?

In two separate case reports, alopecia (hair loss) was reported with Xolair treatment.

Three women, 38, 62 and 70 years of age, with chronic spontaneous urticaria received treatment with omalizumab (Xolair) 300 mg. They had failed treatment with non-sedating antihistamines, ranitidine and montelukast. One patient reported having Hashimoto’s thyroiditis, which has been associated with hair loss, but was not in this case report.

  • Four weeks after treatment, via a self-answered quality-of-life questionnaire, all women reported experiencing side effects (hair loss) “very often” due to treatment. All women reported it as a major, distressing side effect. However, all 3 patients agreed to continued treatment and had significant improvement in their symptoms.
  • The woman with Hashimoto’s thyroiditis took 100 mcg levothyroxine sodium daily for the past 12 months. Her condition was found to be under control by medical examination.
  • The hair loss side effect in all 3 women proved to be transient, lasting 3 to 4 months, and required no special treatment. One patient at the time of the case publication still reported acceptable hair loss that did not seriously affect her quality of life.
  • The authors speculate that Xolair may interfere with mast cell release, and mast cells can have an influence on the hair growth cycle. They also state that because hair loss is transient (meaning usually short-lived) with omalizumab, treatment should continue in patients showing a benefit from the medicine.

In another case report, a 27-year woman was admitted to the hospital with chronic spontaneous urticaria for 3 weeks. She previously had no effect with non-sedating antihistamines, prednisolone, and montelukast (Singulair) treatment for her hives.

  • After 3 days she received treatment with omalizumab (Xolair) 300 mg. Her symptoms reduced quickly and she was discharged the next day. However, her symptoms recurred and she received dapsone 100 mg daily and the omalizumab schedule was increased to 300 mg every 2 weeks. After 2 weeks her symptoms were gone, the dapsone treatment was stopped and the omalizumab was returned to an every 4 week schedule.
  • After 3 months of treatment with omalizumab, the patient reported that she had lost about one-third of her scalp hair, without visible alopecia areata (circular patches). The patient continued treatment with no symptoms of urticaria (hives). After 2 months, the patient reported regrowth of her hair.
  • The patient stopped omalizumab treatment after 10 months as she was symptom-free, but she experienced a flare-up shortly thereafter. Retreatment was started with 300 mg of omalizumab given every 6 weeks. In the retreatment phase, the patient experienced no hair loss or any other side effects.

Related questions

Does Xolair cause alopecia areata?

Alopecia areata has also been reported with the use of Xolair for chronic hives.

Alopecia areata, an autoimmune disorder, leads to hair loss with circular patches and can occur when the immune system attacks the hair follicles.

  • A 27-year old man with chronic hives received Xolair at a single dose of 300 mg per month for 6 months. He improved after the first month, but after 14 weeks of treatment, he reported patches of hair loss on his scalp. Due to the distressing side effect, he was treated with intralesional triamcinolone acetonide, 5 mg per mL every 4 weeks.
  • Although this single case report cannot be attributed solely to Xolair use, the authors speculate that downregulation of mast cell activity or T-helper cells by Xolair may have a role in drug-induced alopecia areata. ​​

Bottom Line

  • Hair loss (alopecia) has been reported in clinical studies with Xolair in at least 2% of people being treated for chronic hives.
  • Hair loss has also been noted in several case reports with Xolair. The hair loss effect appears to be transient, lasting from 3 to 4 months. Alopecia areata has also been associated with Xolair use.
  • Due to limited clinical data, the exact cause of hair loss or how often it occurs is not fully known. If you have concerns about hair loss after starting treatment with Xolair, talk with your healthcare provider.

This is not all the information you need to know about Xolair (omalizumab) for safe and effective use and does not take the place of your doctor’s directions. Review the full product information and discuss this information and any questions you have with your doctor or other healthcare provider.

  • Ghazanfar MN, Thomsen SF. Transient hair loss in patients with chronic spontaneous urticaria treated with omalizumab. Eur Ann Allergy Clin Immunol. 2017;49(6):284-285. doi:10.23822/EurAnnACI.1764-1489.08
  • Konstantinou GN, Chioti AG, Daniilidis M. Self-reported hair loss in patients with chronic spontaneous urticaria treated with omalizumab: an under-reported, transient side effect? Eur Ann Allergy Clin Immunol. 2016 Sep;48(5):205-7. PMID: 27608479.
  • Magen Eli. ​​Alopecia Areata after Omalizumab Treatment for Chronic Spontaneous Urticaria. Acta Derm Venereol 2019; 99: 919–920. doi: 10.2340/00015555-3244
  • Xolair (omalizumab) prescribing information. 2/2024. Genentech. South San Francisco, CA. Accessed Feb. 21, 2024 at

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