Benlysta (belimumab) is a prescription drug that’s used to treat lupus and complications of lupus. The drug can be given as an intravenous (IV) infusion or as an injection under the skin.
Together with other medications, Benlysta is used in adults and some children to treat:
Benlysta belongs to a group of drugs called monoclonal antibodies. Its active ingredient is belimumab. (An active ingredient is what makes a drug work.)
It comes in two forms:
- a liquid solution in prefilled syringes or injection pens for injection under the skin
- a powder that’s dissolved in sterile water and given as an IV infusion (an injection into your vein given over time)
This article describes the dosages of Benlysta, as well as its strengths and how to use it. To learn more about Benlysta, see this in-depth article.
The recommended dosage of Benlysta depends on whether the drug is being used to treat systemic lupus erythematosus (SLE) or lupus nephritis.
It also depends on whether the drug is given as an intravenous (IV) infusion or as an injection under the skin.
Loading doses may be given to quickly increase the amount of drug in your body. This helps the drug start working sooner.
The table below highlights the basics of Benlysta’s dosage for adults. Doses are listed in milligrams (mg) or milligrams of drug per kilogram of body weight (mg/kg). One kilogram is approximately 2.2 pounds.
Keep reading for more details about Benlysta’s dosage.
| Condition | How drug is given | Loading dosage | Maintenance dosage |
| SLE | IV infusion | 10 mg/kg once every 2 weeks for three doses | 10 mg/kg once every 4 weeks |
| SLE | injection under the skin | — | 200 mg once per week |
| lupus nephritis | IV infusion | 10 mg/kg once every 2 weeks for three doses | 10 mg/kg once every 4 weeks |
| lupus nephritis | injection under the skin | 400 mg once per week for four doses | 200 mg once per week |
What are the forms of Benlysta?
Benlysta comes in two forms:
- a liquid solution in a prefilled syringe or injection pen for injection under the skin
- a powder that’s dissolved in sterile water to be given as an IV infusion
What strengths does Benlysta come in?
Benlysta liquid solution comes in one strength: 200 mg per milliliter (mg/ml).
Benlysta powder comes in two strengths: 120 mg and 400 mg.
What are the usual dosages of Benlysta?
The information below describes dosages that are commonly used or recommended. But your doctor will determine the best dosage to fit your needs.
Dosage for systemic lupus erythematosus (SLE)
If you have SLE, you may receive Benlysta as an IV infusion or as an injection under the skin.
If receiving Benlysta as an IV infusion, your dose will be 10 mg/kg. When you first start your treatment, you’ll receive this dose every 2 weeks. This will be continued for a total of 3 doses. This loading dosage helps build up the drug in your body so it can begin to ease your symptoms.
After 3 doses, the frequency will decrease to a dose every 4 weeks. This is the maintenance dosage.
If you’re injecting Benlysta under your skin, you’ll inject a dose of 200 mg once per week. A loading dose isn’t required.
Dosage for lupus nephritis
If you have lupus nephritis, you may receive Benlysta as an IV infusion or as an injection under the skin.
When you first start treatment, you’ll be prescribed a loading dosage. This loading dosage helps build up the drug in your body so it can begin to ease your symptoms. Once you’ve finished with the loading dosage, you’ll start your maintenance dosage.
If receiving Benlysta as an IV infusion, your dose will be 10 mg/kg. When you first start your treatment, you’ll receive this dose every 2 weeks. This will be continued for a total of 3 doses. After 3 doses, the frequency will decrease to a dose every 4 weeks. This is the maintenance dosage.
If you’re injecting Benlysta under your skin, you’ll start with a loading dosage of 400 mg once per week. This is continued for four doses.
After these four doses, you’ll decrease the dosage to 200 mg once per week. This will be your maintenance dosage.
What’s the dosage of Benlysta for children?
Benlysta can be prescribed to children who are ages 5 years and older. It can be used to treat SLE or lupus nephritis. It’s given as an IV infusion.
The table below highlights the basics of Benlysta’s dosage for children.
| Condition | Loading dosage | Maintenance dosage |
| SLE | 10 mg/kg once every 2 weeks for three doses | 10 mg/kg once every 4 weeks |
| lupus nephritis | 10 mg/kg once every 2 weeks for three doses | 10 mg/kg once every 4 weeks |
When children first start treatment with Benlysta, they’ll receive a dose every 2 weeks. After three doses, they’ll receive their dose every 4 weeks. The dose of Benlysta depends on their body weight.
Is Benlysta used long term?
Yes, Benlysta is usually used as a long-term treatment. If you and your doctor determine that it’s safe and effective for your condition, you’ll likely use it long term.
The dosage of Benlysta you’re prescribed may depend on several factors. These include:
- the type and severity of the condition you’re using the drug to treat
- the form of Benlysta you’re using
- your body weight
- other conditions you may have
Benlysta can be given as an intravenous (IV) infusion (an injection into your vein that’s given over time) or as an injection under the skin. The information below provides details on receiving Benlysta.
For information on the expiration, storage, and disposal of Benlysta, see this article.
Receiving Benlysta as an IV infusion
If you’re receiving Benlysta as an IV infusion, you’ll likely receive it at your doctor’s office or another healthcare facility. In some situations, a healthcare professional may come to your home to give you the medication.
Benlysta comes as a powder that’s mixed with sterile water to make a liquid solution. It’s given slowly as an IV infusion over an hour.
Sometimes other medications are given before Benlysta to help prevent an allergic reaction.
Receiving Benlysta as an injection under the skin
Benlysta can also be given as an injection under the skin. If this is how you’ll be receiving Benlysta, your doctor will prescribe the liquid solution. It will come in a prefilled syringe or injection pen.
At your doctor’s office, you’ll be taught how to give yourself an injection. The medication can be injected under the skin of your abdomen or thigh. You’ll want to rotate injection sites to prevent damage to your skin. This means you should not inject Benlysta in the same spot twice in a row.
Accessible drug containers and labels
Some pharmacies provide medication labels that:
- have large print or use braille
- feature a code you can scan with a smartphone to change the text to audio
Your doctor or pharmacist may be able to recommend pharmacies that offer these accessibility features if your current pharmacy doesn’t.
If you’ve missed your appointment to receive Benlysta as an intravenous (IV) infusion, call your doctor’s office as soon as you remember to reschedule.
If you receive Benlysta as an injection under the skin and you miss a dose, you should give yourself the injection as soon as you remember. You can then resume your dosing schedule on the day of the week you usually receive Benlysta. Or if you prefer, you can start a new schedule using the day of the week you took the missed dose on.
If you have questions about when you should give yourself your next injection after missing a dose, talk with your doctor or pharmacist.
If you need help remembering to take your dose of Benlysta on time, try using a medication reminder. This can include setting an alarm or downloading a reminder app on your phone.
Do not use more Benlysta than your doctor prescribes as this can lead to harmful effects.
What to do in case you use too much Benlysta
Call your doctor right away if you think you’ve injected too much Benlysta. You can also call 800-222-1222 to reach America’s Poison Centers or use its online resource. But if you have severe symptoms, immediately call 911 (or your local emergency number) or go to the nearest emergency room.
The sections above describe the usual dosages provided by the drug manufacturer. If your doctor recommends Benlysta for you, they’ll prescribe the dosage that’s right for you.
Remember, you should not change your dosage of Benlysta without your doctor’s recommendation. Only take Benlysta exactly as prescribed. Talk with your doctor if you have questions or concerns about your current dosage.
Here are some examples of questions you may want to ask your doctor:
- If Benlysta isn’t working for me, should my dosage be increased?
- If I’ve been receiving Benlysta as an intravenous (IV) infusion can my doctor change my prescription so I can give myself injections at home?
- Do I need to give myself two injections for the loading dose?
To learn more about Benlysta, see these articles:
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Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.
