Key takeaways

  • Neulasta is a prescription injection used to lower infection risk in people with certain cancers and to treat radiation sickness. As with other drugs, Neulasta may cause side effects that range from mild to serious.
  • The most commonly reported side effects of Neulasta are bone pain and arm or leg pain. These side effects are typically mild, temporary, and easily managed.
  • More serious side effects of Neulasta include acute respiratory distress syndrome (ARDS), ruptured spleen, and inflammation in certain blood vessels. These side effects aren’t common, but they may cause long-term complications without treatment.

For more information about Neulasta, including details about its uses, see this in-depth article on the drug.

The most commonly reported side effects of Neulasta were typically mild. These include:

In most cases, these side effects should be temporary, and some may be easily managed, too. But if you have any symptoms that are ongoing or that bother you, talk with your doctor or pharmacist. And do not stop using Neulasta unless your doctor recommends it.

Neulasta may cause mild side effects other than the ones listed above. To find out more, see Neulasta’s patient information.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks and reviews side effects of the medication. Sharing your experience helps make medication safer for everyone by giving doctors and researchers more information about how the drug works in real life. If you develop a side effect while receiving Neulasta and want to tell the FDA about it, visit MedWatch or call 800-FDA-1088.

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Serious side effects from Neulasta aren’t common, but they can occur in rare cases.

Serious side effects that have been reported with Neulasta include:

If you develop serious side effects while using Neulasta, call your doctor right away. If the side effects seem life threatening or if you think you’re having a medical emergency, immediately call 911 or your local emergency number.

Allergic reaction

In some cases, Neulasta can cause an allergic reaction.

Serious allergic reactions, including anaphylaxis, have been reported with Neulasta.

What you can do

If you have mild symptoms of an allergic reaction, such as a mild rash, call your doctor right away. They may suggest a treatment to manage your symptoms and can determine whether you should keep receiving Neulasta.

If you have symptoms of a severe allergic reaction, such as swelling or trouble breathing, call 911 or your local emergency number right away. These symptoms could be life threatening and require immediate medical care.

If your doctor confirms you’ve had a serious allergic reaction to Neulasta, they may have you switch to a different treatment.

Get answers to some frequently asked questions about Neulasta’s side effects.

Most people who get side effects from Neulasta only have mild symptoms. These should go away on their own after a few days. Side effects of the Neulasta shot or patch usually aren’t long in duration.

Before you start treatment with Neulasta, talk with your doctor and pharmacist about potential side effects. This should include long-term and short-term side effects.

Although very rare, Neulasta may cause a ruptured spleen. For more information, see the “Side effects explained” section below.

Other serious side effects, including leukocytosis and glomerulonephritis, can usually be treated and should go away when you stop using Neulasta. Leukocytosis is an increased level of white blood cells called leukocytes. Glomerulonephritis is a condition that affects your kidneys. For more information about glomerulonephritis, see the “Side effects explained” section below.

If you have questions about how long Neulasta side effects can last, talk with your doctor or pharmacist.

Learn more about some of the side effects Neulasta may cause.

Bone pain

Bone pain is a common side effect of Neulasta, though the reason for this isn’t known. It also isn’t known how long this side effect from the drug can last.

What might help

If you develop bone pain while using Neulasta, contact your doctor. They may suggest you take a pain reliever, such as ibuprofen (Advil, Motrin) or naproxen (Aleve). Or they may recommend you stop using Neulasta.

Ruptured spleen

Although it’s very rare, people prescribed Neulasta may develop a ruptured spleen. There have been reports of this side effect in people using Neulasta. But it’s unclear how often this side effect happened or if Neulasta was the cause.

Symptoms of a ruptured spleen include:

What might help

A ruptured spleen is a life threatening condition that needs immediate medical attention. If you’re using Neulasta and have pain in your left shoulder or upper-left abdomen, call 911 or go to an emergency room right away.

Acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) is a rare, serious side effect of Neulasta. With this condition, your lungs become filled with fluid. This keeps your lungs from being able to supply your body with enough oxygen.

There have been reports of this side effect in people using Neulasta. But it’s unclear how often this side effect has happened or if Neulasta was the cause.

Symptoms of ARDS include:

What might help

Although very rare, ARDS can be life threatening, so it needs immediate medical attention. If you’re using Neulasta and feel short of breath or are having trouble breathing, call 911 or go to an emergency room right away.

Glomerulonephritis

Glomerulonephritis causes swelling in the glomeruli, which are blood vessel clusters in your kidneys. These organs help filter waste products out of your blood and into your urine.

There have been reports of glomerulonephritis in people using Neulasta. But it’s unclear how often this side effect has happened or if Neulasta was the cause.

Symptoms of this side effect include:

What might help

If you think you have symptoms of glomerulonephritis while using Neulasta, call your doctor. Usually, reducing your dose can help treat this side effect. But if this doesn’t work, your doctor may recommend trying a different drug to treat your condition.

Before taking Neulasta, discuss your health history with your doctor. Neulasta may not be right for you if you have certain medical conditions or other factors affecting your health. Be sure to talk with your doctor if any of the following apply to you:

  • allergy to acrylic or latex
  • myeloid cancer (a kind of cancer involving bone marrow)
  • sickle cell disorders
  • previous allergic reaction to Neulasta
  • pregnancy or breastfeeding
  • regular alcohol consumption

Side effects from Neulasta aren’t common, and they’re usually mild when they do occur. Mild side effects of Neulasta are bone pain and pain in your arms or legs. Serious side effects from Neulasta can occur in rare cases.

If you have questions about Neulasta’s side effects, talk with your doctor or pharmacist. Ask questions to get the answers you need to feel confident about your treatment. Here are a few to get you started:

  • What can I do to lower my risk for side effects from Neulasta?
  • Are there other things I can do to manage side effects from Neulasta?
  • Are there any side effects from Neulasta that I’m at higher risk for?

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Q:

My doctor prescribed Neulasta Onpro for me. What happens if it doesn’t give my dose correctly? Am I at higher risk for side effects if this happens?

Anonymous

A:

There have been reports of people who used Neulasta Onpro missing doses or receiving incomplete doses of medication. This was due to the on-body injector (OBI) not working correctly. If you miss a dose or receive an incomplete dose, you could be at higher risk for certain side effects. Examples include neutropenia (low level of neutrophils, a type of white blood cell), febrile neutropenia (neutropenia with a fever), and infection.

If you think your Neulasta Onpro device isn’t working as intended, contact your doctor right away.

The Healthline Pharmacist TeamAnswers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.

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.