Belimumab (Benlysta)

Belimumab is an immunosuppressant used for the treatment of systemic lupus and lupus nephritis in children and adults. Belimumab can be used in combination with other medications such as hydroxychloroquine and steroids. Belimumab can improve the signs and symptoms of SLE including inflammation of the blood vessels, skin, joints, and kidneys.

How To Take It

Belimumab can be given as an infusion or injection. When given by infusion, the medication is administered through an IV. The infusion is given in a healthcare facility or at home under supervision, and lasts about one hour. The dose is based on your weight. Infusions are every two weeks for the first 3 doses and every four weeks, thereafter. Belimumab may take some time to work, but most people start to feel better after 12 weeks, though it can take longer in some patients and for those with lupus nephritis.

Belimumab is also available as an autoinjector (e.g., self-injection). This means you can give the medication to yourself by injecting it under the skin once a week. The autoinjectors are preloaded with 200 mg of medication.

Side Effects

Common side effects of belimumab include fever, diarrhea, nausea, muscle aches, headache, trouble sleeping, and infections, such as colds, bronchitis, and urinary tract infections. You may also experience redness, itching, or swelling at the site of your injection.

Belimumab can lower the number of white blood cells in the blood of some people. Rarely, it can also cause you to feel down and have depressive thoughts, which are reversable when stopping the medicine.

To know if belimumab is causing side effects, keep track of how long the symptoms last and whether they come back after your next infusion or injection. If so, discuss this with your rheumatology provider.

Tell Your Rheumatology Provider

Before using belimumab, tell your rheumatology provider if you plan to become pregnant. It is unknown if belimumab is safe for pregnant women to take. You should not try to become pregnant or breastfeed while taking this drug. If you do become pregnant, immediately tell your doctor.

Tell your rheumatology provider if you feel unwell, have an infection, a history of cancer, or a history of depression or new symptoms of depression or anxiety.

Many vaccines, such as the flu shot, pneumonia shot, and new shingles vaccine (Shingrix), are safe while taking belimumab; but others, such as live vaccines (Zostrix), are not. Talk to your doctor about getting vaccines before starting belimumab.

Updated May 2026 by Fotios Koumpouras, MD, and reviewed by the American College of Rheumatology Committee on Communications and Marketing.

This information is provided for general education only. Individuals should consult a qualified healthcare provider for professional medical advice, diagnosis and treatment of a medical or health condition.