Benlysta (Belimumab) - Intravenous, Subcutaneous

What Is Benlysta?

Benlysta (belimumab) is a prescription rheumatologic medication used to treat an autoimmune condition called lupus and lupus nephritis, a form of lupus that affects the kidneys. It belongs to a class of medications known as monoclonal antibodies.

Certain cells that react against the body are known as autoreactive B cells. One of the important proteins for the growth of these B cells is called B-lymphocyte stimulator, or BLyS. Benlysta works by binding to BLyS, which means that BLyS can no longer bind to and activate the autoreactive B cells. By doing this, Benlysta helps decrease disease activity.

Benlysta is available as a subcutaneous (under the skin) or intravenous (IV) injection.

Drug Facts

Generic Name: Belimumab

Brand Name(s): Benlysta

Drug Availability: Prescription

Therapeutic Classification: Immunological agent

Available Generically: No

Controlled Substance: N/A

Administration Route(s): Subcutaneous, Intravenous

Active Ingredient: Belimumab

Dosage Form(s): Solution, powder for solution

What Is Benlysta Used For?

The Food and Drug Administration (FDA) approved Benlsyta to treat:

  • Systemic lupus erythematosus in people aged 5 years and older being treated with other therapies
  • Lupus nephritis (inflammation of the kidneys) in adults who are also being treated with other therapies
Benlysta (Belimumab) Drug Information - Illustration by Zoe Hansen

Verywell / Zoe Hansen

How to Take Benlysta

Benlysta is available as an IV infusion (through the vein) given by a healthcare provider or a subcutaneous injection, which you can give yourself as instructed by a healthcare provider. 

If you use the subcutaneous injection, your healthcare provider will tell you how and when to administer your dose. The subcutaneous form comes in either a single-dose prefilled syringe or a single-dose autoinjector. It is usually administered once a week on the same day each week. One dose may include two injections if you use it for lupus nephritis. You will administer the injection under the skin, either in your stomach or thigh.

For the IV form of Benlysta, your healthcare provider will let you know when and how often you should receive your infusion. This will be administered to you in a healthcare setting under the supervision of a healthcare provider. It takes about one hour to receive a full dose through the infusion.


People should store the injection form of Benlysta in its original carton in the refrigerator. Do not freeze or shake the injections. You can keep Benlysta out of the refrigerator for up to 12 hours if kept out of sunlight. You should not use it or store it in the refrigerator if it is left out for longer than 12 hours.

What Are the Side Effects of Benlysta?

This is not a complete list of side effects and others may occur. A healthcare provider can advise you on side effects. If you experience other effects, contact your pharmacist or a healthcare provider. You may report side effects to the FDA at or 1-800-FDA-1088.

Common Side Effects

The most common side effects with Benlysta include:

  • Pain, redness, itching, or swelling at the injection site
  • Nausea
  • Diarrhea
  • Bronchitis
  • Trouble sleeping
  • Fever
  • Pain in arms or legs
  • Migraine
  • Depression

If any of these side effects don’t go away or become more severe, talk to your healthcare provider or pharmacist.

Severe Side Effects

Call your healthcare provider right away if you have serious side effects. Call 911 if your symptoms feel life-threatening or if you think you’re having a medical emergency. Serious side effects and their symptoms can include the following:

  • Severe allergic reactions: Symptoms may include trouble breathing, hives, swelling of the tongue, lips, mouth, or throat
  • Severe infections

Report Side Effects

Benlysta may cause other side effects. Call your healthcare provider if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your provider may send a report to the FDA's MedWatch Adverse Event Reporting Program or by phone (800-332-1088).

Dosage: How Much of Benlysta Should I Take?

Drug Content Provided and Reviewed by IBM Micromedex®

The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

  • For injection dosage form (solution):
    • For systemic lupus erythematosus:
      • Adults—200 milligrams (mg) injected under your skin once a week, preferably on the same day each week.
      • Children—Should not be used in this age group.
    • For lupus nephritis:
      • Adults—At first, 400 milligrams (mg) (two 200-mg injections) injected under your skin once a week for 4 doses, then 200 milligrams once a week, preferably on the same day each week.
      • Children—Should not be used in this age group.


Subcutaneous dosing is not approved for people under the age of 18. However, people aged 5 years and older may receive Benlysta as an IV infusion. Your healthcare provider will determine which administration method is right for you.

Missed Dose

If you miss a dose of Benlysta, administer the missed dose as soon as you remember. Then, you can either resume taking your dose on the usual day of administration or start a new weekly schedule from the day you administered the missed dose.

Overdose: What Happens If I Take Too Much Benlysta?

There is limited experience with overdose and Benlysta. Side effects of taking too much Benlysta are expected to be the same as common side effects.

What Happens If I Overdose on Benlysta?

If you think you or someone else may have overdosed on Benlysta, call a healthcare provider or the Poison Control Center (800-222-1222).

If someone collapses, has a seizure, has trouble breathing, or can’t wake up after taking too much Benlysta, call 911 immediately.


Drug Content Provided and Reviewed by IBM Micromedex®

It is very important that your doctor check your or your child's progress closely and at regular visits to make sure this medicine is working properly and to decide if you should continue to receive it. Blood and urine tests may be needed to check for unwanted effects.

You should not receive this medicine if you are also using other biologic treatments or cyclophosphamide (Cytoxan®). Using these medicines together may increase your chance for more serious side effects.

Using this medicine while you are pregnant can harm your unborn baby. Use an effective form of birth control during treatment and for at least 4 months after the last dose. If you think you have become pregnant while using this medicine, tell your doctor right away.

This medicine may cause serious infections (eg, pneumonia, urinary tract infections, cellulitis, and bronchitis). Check with your doctor right away if you have bladder pain, bloody or cloudy urine, chest pain, cough, cough producing mucus, difficult, burning, or painful urination, fever or chills, frequent urge to urinate, itching, pain, redness, swelling, tenderness, or warmth of the skin, lower back or side pain, sneezing, sore throat, trouble breathing, or tightness in the chest.

This medicine may increase your risk of developing infections, including a serious brain infection called progressive multifocal leukoencephalopathy (PML). Avoid being near people who are sick and wash your hands often. Check with your doctor right away if you have a fever, chills, a cough that won't go away, flu-like symptoms, a headache, night sweats, or weight loss. Tell your doctor if you have balance problems, confusion, difficulty talking or walking, dizziness, memory loss, or vision changes.

Using this medicine may increase your risk of getting cancer. Talk to your doctor if you have concerns about this risk.

Belimumab may cause infusion reactions, which can be life-threatening and require immediate medical attention. Tell your doctor right away if you start to have a fever, chills or shaking, dizziness, trouble breathing, itching or rash, lightheadedness or fainting, after receiving this medicine.

This medicine may cause serious allergic reactions, including anaphylaxis, which can be life-threatening and require immediate medical attention. Tell your doctor right away if you have a rash, itching, hoarseness, trouble breathing, trouble swallowing, or any swelling of your hands, face, or mouth after using this medicine.

This medicine may cause some people to be agitated, irritable, or display other abnormal behaviors. It may also cause some people to have suicidal thoughts and tendencies or to become depressed. Also tell your doctor if you have sudden or strong feelings, such as feeling nervous, angry, restless, violent, or scared. If you or your caregiver notice any of these unwanted effects, tell your doctor right away.

While you are being treated with belimumab, and 30 days before starting treatment with it, do not have any immunizations (vaccines) without your doctor's approval. Belimumab may lower your body's resistance and the vaccine may not work as well or you might get the infection the vaccine is meant to prevent. In addition, you should not be around other persons living in your household who are receiving live virus vaccines because there is a chance they could pass the virus on to you. Some examples of live vaccines include measles, mumps, influenza (nasal flu vaccine), poliovirus (oral form), rotavirus, and rubella. Do not get close to them and do not stay in the same room with them for very long. If you have questions about this, talk to your doctor.

Tell your doctor if you are African-American or have African ancestry. This medicine may not work the same way and may require caution in African-American patients receiving belimumab. Talk to your doctor if you have concerns.

What Are Reasons I Shouldn’t Take Benlysta?

There are a few reasons why your healthcare provider may not choose Benlysta as part of your treatment plan.


A person should not take Benlysta if they are allergic to the ingredients.


It is unclear if Benlysta causes risk during pregnancy. It is best to talk to your healthcare provider if you are pregnant or plan to become pregnant, so they can decide the best option for you.


It isn’t known if Benlysta passes into human milk, but it is possible it can cause serious harm to a child that is breastfed. Talk with your healthcare provider if you are breastfeeding to discuss the best plan for you.

Older Adults

A person 65 years or above often processes drugs more slowly. A lower dose or different schedule may be required.


A person should not receive live vaccines while taking Benlysta. Talk with your healthcare provider before receiving any vaccines.

Other Health Conditions

In certain individuals, the body may handle Benlysta differently. A person should inform their healthcare provider if they have:

  • Progressive multifocal leukoencephalopathy 
  • Depression

What Other Medications Interact With Benlsyta?

There have not been any drug interaction studies for Benlysta yet.

However, before taking Benlysta, tell your healthcare provider about all of the prescription medications, over-the-counter (OTC) medications, vitamins, supplements, or herbs you are taking. This will help you avoid potential interactions. If you have any questions about drug interactions, speak with your healthcare provider or pharmacist.

What Medications Are Similar?

Benlysta is a medication known as a rheumatologic used to treat lupus. There are a few other classes of medications that can also be used for lupus.

A few examples of medications in those classes include:

  • Medrol (methylprednisolone)
  • Arava (leflunomide)
  • Aleve (naproxen sodium)


Methylprednisolone is part of a class of medications known as corticosteroids. They work by decreasing inflammation. Medrol is available as an oral tablet. At high doses, it can be prescribed to help with the inflammation of serious diseases such as lupus. The most common side effects include weight gain, easy bruising, diabetes, and high blood pressure.


Leflunomide belongs to a class of medications known as disease-modifying antirheumatic drugs (DMARDs). DMARDs work by calming your body’s overactive immune system. This can help reduce inflammation. Arava is available as an oral tablet. It is often prescribed to treat rheumatoid arthritis. However, it may be helpful in serious cases of lupus. Common side effects include itchiness, diarrhea, low energy level, or nausea.


Naproxen is part of a class of medications known as non-steroidal anti-inflammatory drugs (NSAIDs). They work by preventing inflammation. Aleve is available as an oral tablet. It is an OTC medication that can be used to help relieve the pain, swelling, or fever associated with lupus. Common side effects include stomach irritation, ulcers, or kidney damage.

This is a list of examples of similar medications. It is not a list of drugs recommended to take with Benlysta. Ask your pharmacist or healthcare provider if you have any questions.

Frequently Asked Questions

  • What is Benlysta used for?

    Benlysta is a monoclonal antibody and part of a class of medication known as rheumotologics. It is often used to treat systemic lupus erythematosus as well as lupus nephritis, or inflammation of the kidneys.

  • What are the side effects of Benlysta?

    The most common side effects are nausea, migraine, fever, or depression. Benlysta also has the potential for serious side effects such as an allergic reaction or severe infection. Talk to your healthcare provider about any side effects you experience.

  • How do I store Benlysta?

    Benlysta injections should be stored in the refrigerator. Do not freeze them. It is best to keep the product in the original carton and protect it from light.

How Can I Stay Healthy While Taking Benlysta?

Living with lupus can be difficult, but taking your medication as prescribed can help reduce your disease progression and flares.

Benlysta is a safe and effective therapy when used correctly.  While Benlysta does have the potential for serious side effects, such as allergic reactions or severe infection, the most common side effects may be milder. Those tend to include nausea, diarrhea, migraine, or fever. 

Inform your healthcare provider of all the current medications you take and check with them before starting any new ones. This way, your healthcare provider can determine what treatment and what dose will work best for you.

Medical Disclaimer

Verywell Health's drug information is meant for educational purposes only and is not intended to replace medical advice, diagnosis, or treatment from a healthcare provider. Consult your healthcare provider before taking any new medication(s). IBM Watson Micromedex provides some of the drug content, as indicated on the page.

5 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. U.S. Library of Medicine. DailyMed. Label: Benlysta - belimumab injection, powder, lyophilized, for solution. Benlysta- belimumab solution.

  2. Food and Drug Administration. Benlysta label.

  3. U.S. Library of Medicine. DailyMed. Medrol - methylprednisolone tablet.

  4. U.S. Library of Medicine. DailyMed. Arava - leflunomide film coated tablets.

  5. U.S. Library of Medicine. DailyMed. Aleve - naproxen sodium tablet.

By Kaylea Swearingen, PharmD
Kaylea Swearingen is a registered pharmacist and health and wellness writer.