Skip to Content


Generic Name: belimumab (be LIM ue mab)
Brand Names: Benlysta

Medically reviewed by J. Stewart, BPharm Last updated on Apr 26, 2019.

What is Benlysta?

Benlysta (belimumab) is a monoclonal antibody that affects the actions of the body's immune system. Monoclonal antibodies are made to target and destroy only certain cells in the body. This may help to protect healthy cells from damage.

Benlysta is used to treat active systemic lupus erythematosus (SLE) in adults and children aged five years and above.

Benlysta is not for use in people who have severe kidney problems caused by SLE, or have active SLE that affects the central nervous system (brain, nerves, and spinal cord).

Important Information

When Benlysta is injected into a vein, tell your caregiver right away if you feel anxious, nauseated, light-headed, itchy, or short of breath.

Serious and sometimes fatal infections may occur. Stop using Benlysta and call your doctor right away if you have signs of infection such as: fever, chills, cough with mucus, pain or burning when you urinate, urinating more than usual, or skin sores.

Benlysta may also cause heart problems. Call your doctor at once if you have chest pain, nausea, dizziness, sweating, and trouble breathing.

This medicine may cause mental health problems. Report any new or worsening mental health symptoms to your doctor, such as: depression, mood or behavior changes, trouble sleeping, or thoughts about hurting yourself or others.

Before taking this medicine

You should not use Benlysta if you are allergic to belimumab.

To make sure Benlysta is safe for you, tell your doctor if you have ever had:

  • an active or chronic infection;

  • depression or mental illness;

  • suicidal thoughts or actions;

  • cancer; or

  • if you are using cyclophosphamide, biologic medicines, or other monoclonal antibody medicines.

Some people have thoughts about suicide while using Benlysta. Your doctor will need to check your progress at regular visits. Your family or other caregivers should also be alert to changes in your mood or symptoms.

Belimumab may increase your risk of certain cancers by changing the way your immune system works. Ask your doctor about your individual risk.

Belimumab may harm an unborn baby. Use effective birth control to prevent pregnancy while you are using this medicine and for at least 4 months after your last dose. Tell your doctor if you become pregnant.

If you are pregnant, your name may be listed on a pregnancy registry to track the effects of belimumab on the baby.

It may not be safe to breast-feed while using this medicine. Ask your doctor about any risk.

Benlysta is not approved for use by anyone younger than 18 years old.

How is Benlysta given?

Benlysta is given as an infusion into a vein, usually every 2 to 4 weeks. A healthcare provider will give you this injection. The medicine must be given slowly, and the infusion can take about 1 hour to complete.

Benlysta is also injected under the skin, usually once per week. A healthcare provider may teach you how to properly use the medication by yourself. Do not inject this medicine into skin that is bruised, tender, red, or hard.

If you give injections at home, use the medicine on the same day each week. Read and carefully follow any Instructions for Use provided with your medicine. Do not use Benlysta if you don't understand all instructions for proper use. Ask your doctor or pharmacist if you have questions.

Prepare your injection only when you are ready to give it. Do not use if the medicine has changed colors or has particles in it. Call your pharmacist for new medicine.

You may be given other medications to help prevent serious side effects or an allergic reaction. Keep using these medicines for as long as your doctor has prescribed.

Store the prefilled syringe or injection pen in its original packaging in the refrigerator. Do not freeze or expose to light or high heat. Avoid shaking the medicine.

Take the package out of the refrigerator to let the medicine reach room temperature for 30 minutes before injecting your dose. Protect from light and do not shake or heat the medicine.

Do not use Benlysta if it has been left at room temperature longer than 12 hours. Do not put the medicine back into the refrigerator. Call your pharmacist for new medicine.

Each prefilled syringe or injection pen is for one use only. Throw it away after one use, even if there is still medicine left inside.

Use a needle and syringe only once and then place them in a puncture-proof "sharps" container. Follow state or local laws about how to dispose of this container. Keep it out of the reach of children and pets.

Benlysta dosing information

Usual Adult Dose for Systemic Lupus Erythematosus:

10 mg/kg IV at 2-week intervals for the first 3 doses and at 4-week intervals thereafter.

-Infuse over a 1-hour period.
-Consider premedication including an antihistamine, with or without an antipyretic, before the infusion.

Use: Treatment of adult patients with active, autoantibody-positive, systemic lupus erythematosus (SLE) who are receiving standard therapy.

What happens if I miss a dose?

Use the missed dose as soon as you remember, and then use your next injection 1 week later. You can either restart a weekly schedule based on the new injection day, or you can go back to your regular injection schedule. Do not use 2 injections on the same day.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while using Benlysta?

Avoid being near people who are sick or have infections. Tell your doctor at once if you develop signs of infection.

Do not receive a "live" vaccine while using Benlysta. The vaccine may not work as well and may not fully protect you from disease. Live vaccines include measles, mumps, rubella (MMR), polio, rotavirus, typhoid, yellow fever, varicella (chickenpox), and zoster (shingles).

Benlysta side effects

Get emergency medical help if you have signs of an allergic reaction to Benlysta: hives, itching; feeling anxious or light-headed; difficult breathing; swelling of your face, lips, tongue, or throat.

Some side effects may occur during the injection. Tell your caregiver if you feel anxious, nauseated, light-headed, itchy, or have trouble breathing, severe headache, or skin redness and swelling.

You may get infections more easily, even serious or fatal infections. Stop using Benlysta and call your doctor right away if you have signs of infection such as:

  • fever, chills;

  • cough with mucus;

  • pain or burning when you urinate;

  • urinating more than usual; or

  • bloody diarrhea.

Belimumab may cause a serious brain infection that can lead to disability or death. Call your doctor right away if you have problems with speech, thought, vision, or muscle movement. These symptoms may start gradually and get worse quickly.

Also call your doctor at once if you have:

  • new or worsening depression, anxiety, mood or behavior changes, trouble sleeping, risk-taking behavior, or thoughts about hurting yourself or others;

  • wheezing, chest tightness, trouble breathing; or

  • chest pain or pressure, pain spreading to your jaw or shoulder, nausea, sweating.

Common Benlysta side effects may include:

  • nausea, diarrhea;

  • fever, sore throat, runny or stuffy nose, cough;

  • pain, itching, redness, or swelling where the injection was given;

  • pain in your arms or legs;

  • headache, depressed mood; or

  • sleep problems (insomnia).

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What other drugs will affect Benlysta?

Other drugs may interact with belimumab, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all your current medicines and any medicine you start or stop using.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use Benlysta only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.