Reblozyl (luspatercept-aamt) is a prescription drug that’s used to treat anemia in adults from certain blood disorders. The drug is given as a subcutaneous injection by a healthcare professional. It’s usually given once every 3 weeks.

Reblozyl is used in adults to treat anemia from certain blood disorders, including:

The active ingredient in Reblozyl is luspatercept-aamt. (An active ingredient is what makes a drug work.) Reblozyl belongs to a group of drugs called erythroid maturation agents. It’s a biologic drug made from living cells.

This article describes the dosage of Reblozyl, as well as its strengths and how it’s given. To learn more about Reblozyl, see this in-depth article.

This section describes the usual dosages of Reblozyl. Keep reading to learn more.

What is Reblozyl’s form?

Reblozyl comes as a powder that’s mixed with a liquid to form a solution that is given as a subcutaneous injection (injection under your skin) by a healthcare professional.

What strengths does Reblozyl come in?

Reblozyl comes in two strengths: 25 milligrams (mg) and 75 mg, in single-dose vials.

What are the usual dosages of Reblozyl?

Your doctor will likely start you on the recommended dosage of Reblozyl to treat your condition. They may adjust it over time based on how you respond to treatment.

The information below describes dosages that are commonly used or recommended. Your doctor will determine the best dosage to fit your needs.

Dosage for anemia

The typical starting Reblozyl dosage for adults with anemia from beta-thalassemia or myelodysplastic syndrome (MDS) is based on your body weight. The dosage is 1 mg per kilogram (kg) of body weight. For reference, one kilogram equals about 2.2 pounds (lb). You’ll typically receive a dose once every 3 weeks.

Your doctor will check your hemoglobin levels and blood transfusion history to see how well Reblozyl is working for you. Your doctor may increase, decrease, or keep the same dosage of Reblozyl based on these results.

Beta-thalassemia: For anemia from beta-thalassemia, if you haven’t responded to the 1 mg per kg dose of Reblozyl after 6 weeks (two doses), your doctor may increase your dose to 1.25 mg per kg. This is the maximum dosage of Reblozyl for beta-thalassemia.

They’ll also stop treatment if you don’t respond to Reblozyl after 9 weeks (three doses of Reblozyl).

MDS: For anemia from MDS, depending on how you respond to Reblozyl, your doctor may increase your dosage of the medication gradually. If you haven’t responded to the 1 mg per kg dose of Reblozyl after 6 weeks (2 doses), your doctor may increase your dose to 1.25 mg per kg.

If you do not respond to this dose, your doctor may increase your dose to 1.75 mg per kg. This is the maximum dosage of Reblozyl for MDS. If you still don’t respond to this dose after 3 doses (9 weeks), your doctor may recommend stopping treatment with Reblozyl and discuss other treatment options with you.

If you have questions about your dosage of Reblozyl, talk with your doctor to learn more.

Is Reblozyl used long term?

Yes, Reblozyl 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.

Your doctor will monitor how you respond to treatment and discuss how long you’re likely to use Reblozyl.

The dosage of Reblozyl you’re prescribed may depend on several factors. These include:

Reblozyl is available as a powder that’s mixed into a liquid solution and given as a subcutaneous injection (injection under your skin) by a healthcare professional.

You’ll receive doses once every 3 weeks based on your hemoglobin levels and blood transfusions you’ve received. You’ll receive doses in your doctor’s office, a clinic, or in the hospital.

If you miss an appointment to receive a dose of Reblozyl, call your doctor’s office as soon as possible to reschedule. They’ll check your blood levels and give you a dose of the medication. They’ll also adjust your dosing schedule if needed. Reblozyl is given no sooner than once every 3 weeks based on blood tests and transfusions you’ve received.

If you need help remembering your appointments, try downloading a reminder app on your phone.

Below are answers to some commonly asked questions about Reblozyl’s dosage.

What is the maximum dosage of Reblozyl?

The maximum dosage of Reblozyl depends on the condition the drug is being used to treat.

For anemia from beta-thalassemia, the maximum dose of Reblozyl is 1.25 mg per kg of body weight given once every 3 weeks.

For anemia from MDS, the maximum dosage is 1.75 mg per kg of body weight given once every 3 weeks.

Your doctor will check your hemoglobin levels and blood transfusions you’ve received to determine your dosage and any adjustments you may need.

For more information about the maximum dosage of Reblozyl, see the “What is Reblozyl’s dosage?” section above.

Talk with your doctor if you have questions about your dosage of Reblozyl.

How long does it take for Reblozyl to start working?

Reblozyl starts to work after your first dose, but it may take a few doses before your condition improves. Your doctor will monitor your hemoglobin level and blood transfusions you’ve received before each dose of Reblozyl (every 3 weeks) to check whether the drug is working to treat your condition.

They may adjust your dose, pause it, or completely stop treatment depending on how you respond to Reblozyl.

If you have other questions about what to expect from your Reblozyl treatment, talk with your doctor.

The sections above describe the usual dosages provided by Reblozyl’s manufacturer. If your doctor recommends this drug, they’ll prescribe the dosage that’s right for you.

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:

  • Will my dosage of Reblozyl change if I lose weight?
  • Would I need a dosage adjustment if I’m taking other medications to treat anemia?
  • Is my risk for side effects higher if I receive the maximum dose of Reblozyl?

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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.