Safety & Side Effects

Learn about the side effects of BENLYSTA and the conditions under which you should avoid treatment with BENLYSTA.

Erica, real BENLYSTA patient compensated by GSK

What is the most important information I should know about BENLYSTA?

Immunosuppressive agents, including BENLYSTA, can cause serious side effects. Some of these side effects may cause death.


Fever, chills, pain or burning with urination, urinating often, coughing up mucus, or warm, red, or painful skin or sores on your body. Infections could be serious, leading to hospitalization or death.

Allergic (hypersensitivity) reactions

Itching, swelling of the face, lips, mouth, tongue, or throat, trouble breathing, anxiousness, low blood pressure, dizziness or fainting, headache, nausea, or skin rash. Serious allergic reactions can happen on the day of, or in the days after, receiving BENLYSTA and may cause death.

Mental health problems and suicide

Thoughts of suicide or dying, attempt to commit suicide, trouble sleeping (insomnia), new or worse anxiety or depression, acting on dangerous impulses, other unusual changes in your behavior or mood, or thoughts of hurting yourself or others.

Who should not receive BENLYSTA?

Do not receive BENLYSTA if you:
are allergic to belimumab or any of the ingredients in BENLYSTA. See the end of the Medication Guide for a complete list of ingredients in BENLYSTA.

What should I tell my healthcare provider before receiving BENLYSTA?

Before you receive BENLYSTA, tell your healthcare provider about all of your medical conditions, including if you:

  • think you have an infection or have infections that keep coming back. You should not receive BENLYSTA if you have an infection unless your healthcare provider tells you to. 
  • have or have had mental health problems such as depression or thoughts of suicide.
  • have recently received a vaccination or if you think you may need a vaccination. If you are receiving BENLYSTA, you should not receive live vaccines.
  • are allergic to other medicines.
  • are receiving other biologic medicines or monoclonal antibodies.
  • have or have had any type of cancer. 
  • have any other medical conditions.
  • are pregnant or plan to become pregnant. It is not known if BENLYSTA will harm your unborn baby. You should talk to your healthcare provider about whether to prevent pregnancy while on BENLYSTA. If you choose to prevent pregnancy, you should use an effective method of birth control while receiving BENLYSTA and for at least 4 months after the final dose of BENLYSTA.

    Tell your healthcare provider right away if you become pregnant during your treatment with BENLYSTA or if you think you may be pregnant.
  • become pregnant while receiving BENLYSTA. Talk to your healthcare provider about enrolling in the BENLYSTA Pregnancy Registry. You can enroll in this registry by calling 1-877-681-6296. The purpose of this registry is to monitor the health of you and your baby.
  • are breastfeeding or plan to breastfeed. It is not known if BENLYSTA passes into your breast milk. You and your healthcare provider should talk about whether or not you should receive BENLYSTA and breastfeed.

Tell your healthcare provider about all the medicines you take

including prescription and over-the-counter medicines, vitamins, and herbal supplements. Know the medicines you take. Keep a list of your medicines with you to show to your healthcare provider and pharmacist when you get a new medicine.

How will I receive BENLYSTA?

When administered intravenously (by vein)

  • You will be given BENLYSTA by a healthcare provider through a needle placed in a vein (IV infusion). It takes about 1 hour to give you the full dose of BENLYSTA.
  • Your healthcare provider will tell you how often you should receive BENLYSTA.
  • Your healthcare provider may give you medicines before you receive BENLYSTA to help reduce your chance of having a reaction. A healthcare provider will watch you closely while you are receiving BENLYSTA and after your infusion for signs of a reaction. A healthcare provider will review the signs and symptoms of possible allergic reactions that could happen after your infusion.

When administered subcutaneously (under your skin)

  • Your healthcare provider will tell you how often you should use BENLYSTA. Use BENLYSTA exactly as your healthcare provider tells you to.
  • Read the Instructions for Use that come with BENLYSTA for instructions about the right way to give your injections at home.
  • BENLYSTA may be prescribed as a single-dose autoinjector or as a single-dose prefilled syringe.
  • Before you use BENLYSTA, your healthcare provider will show you or your caregiver how to give the injections and review the signs and symptoms of possible allergic reactions.
  • BENLYSTA is injected under the skin (subcutaneously) of your stomach (abdomen) or thigh.
  • Use BENLYSTA once a week on the same day each week. If you have lupus nephritis, one dose may be 2 injections.
  • If you miss your dose of BENLYSTA on your planned day, inject a dose as soon as you remember. Then, inject your next dose at your regularly scheduled time or continue weekly dosing based on the new day injected. In case you are not sure when to inject BENLYSTA, call your healthcare provider.

What are the possible side effects of BENLYSTA?

BENLYSTA can cause serious side effects, including: 

Progressive multifocal leukoencephalopathy (PML)

PML is a serious and life-threatening brain infection. PML can result in death or severe disability. Tell your healthcare provider right away if you notice any new or worsening medical problems: memory loss, trouble thinking, dizziness or loss of balance, difficulty talking or walking, or loss of vision.


Medicines that affect the immune system, including BENLYSTA, may increase your risk of certain cancers.

The most common side effects of BENLYSTA include:

nausea, diarrhea, fever, stuffy or runny nose and sore throat, persistent cough, trouble sleeping, leg or arm pain, depression, headache, and pain, redness, itching, or swelling at the site of injection (when given subcutaneously).

These are not all the possible side effects of BENLYSTA. Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.