Rebif (interferon beta-1a) is a prescription drug used to treat types of multiple sclerosis. Rebif can cause side effects that range from mild to serious. Examples include flu-like symptoms and abdominal pain.

Specifically, Rebif is used in adults to treat:

The active ingredient in Rebif is interferon beta-1a. It’s a biologic medication that’s made from living cells. Rebif comes as a liquid solution that’s given as an injection under your skin.

Keep reading to learn about common, mild, and serious side effects Rebif can cause. For a general overview of the drug, including details about its uses, see this in-depth Rebif article.

Some people may experience mild to serious side effects during Rebif treatment.

Examples of the drug’s commonly reported side effects include:

* To learn more about this side effect, see the “Side effects explained” section.

Mild side effects have been reported with Rebif. These include:

  • abdominal pain
  • flu-like symptoms
  • injection site reactions
  • fatigue
  • fever
  • headache

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

Rebif may cause mild side effects other than those listed above. See the drug’s prescribing information for details.

Serious side effects have been reported with Rebif. These include:

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

* To learn more about this side effect, see the “Side effects explained” section.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks and reviews side effects of the medication. If you’d like to notify the FDA about a side effect you’ve had with Rebif, visit MedWatch.

ALLERGIC REACTION

For some people, Rebif can cause an allergic reaction.

In general, symptoms of allergic reaction can be mild or serious.

What might help

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 continue Rebif treatment.

If you have symptoms of a severe allergic reaction, such as swelling or difficulty 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 Rebif, they may have you switch to a different treatment.

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

Are there any long-term side effects of Refib?

Yes, some side effects of Rebif may affect you long term. Long-term side effects include those that may start at any time you’re taking a medication, even if you’ve taken it for a long time. It also includes side effects that may not go away, even after you stop treatment with the medication.

Examples of long-term side effects reported in Rebif’s studies include:

  • liver damage, including liver failure
  • thyroid disorder
  • autoimmune disorders such as lupus erythematosus or hepatitis
  • pulmonary arterial hypertension (high blood pressure in the blood vessels of the lungs)
  • serious injection site reaction such as tissue death
  • thrombotic microangiopathy (blood clotting disorder)
  • depression

Note: While suicide was not reported in the drug’s studies, it has been reported in people receiving Rebif treatment since the drug was approved for use. Contact your doctor immediately if you experience symptoms of depression or suicidal thoughts while receiving treatment with this medication.

Talk with your doctor to learn more about possible long-term side effects of Rebif and how long they may last.

Will stopping Rebif suddenly cause side effects?

No, it shouldn’t. But stopping Rebif suddenly may cause your multiple sclerosis (MS) to relapse, which could make your symptoms return or worsen. However, suddenly stopping Rebif treatment shouldn’t cause side effects from the medication. This wasn’t reported in the drug’s studies.

Note: The half life of Rebif is around 69 hours. This is how long it takes for half the medication to leave your body. So a certain amount of Rebif will stay in your system for several days after you receive a dose.

Your doctor will monitor you closely during your treatment with Rebif. If you experience bothersome or serious side effects, contact them right away.

Do not stop Rebif treatment without talking with your doctor first.

Is cancer a side effect of Rebif?

Cancer is not a known side effect of Rebif. It was not reported in the drug’s studies.

Your doctor will monitor you throughout your Rebif treatment. Talk with them about any side effect concerns you may have.

Help is out there

If you or someone you know is in crisis and considering suicide or self-harm, please seek support:

  • Call or text the 988 Suicide and Crisis Lifeline at 988 or chat at 988lifeline.org. Caring counselors are available to listen and provide free and confidential support 24/7.
  • Text HOME to the Crisis Text Line at 741741 to connect with a volunteer crisis counselor for free and confidential support 24/7.
  • Not in the United States? Find a helpline in your country with Befrienders Worldwide.
  • Call 911 or your local emergency services number if you feel safe to do so.

If you’re calling on behalf of someone else, stay with them until help arrives. You may remove weapons or substances that can cause harm if you can do so safely.

If you’re not in the same household, stay on the phone with them until help arrives.

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

Chest pain

Chest pain was a rare but serious side effect of Rebif that was reported in the drug’s studies.

Chest pain may be a symptom of certain other side effects of Rebif such as bone and muscle pain, flu-like symptoms, and injection site reactions.

What might help

If you experience chest pain during Rebif treatment, tell your doctor right away. If you feel your symptoms are life threatening, call 911 or go to the nearest emergency medical center immediately.

Liver damage

Treatment with Rebif can cause liver injury, including hepatitis (liver inflammation) or liver failure, which may be long lasting. While rare, serious types of liver damage were reported in the drug’s studies.

Symptoms of liver problems may include:

What might help

Before starting treatment with Rebif, tell your doctor if you’ve ever had liver problems, including hepatitis. They may order blood tests to check your liver function before prescribing this drug for you.

If you have symptoms of liver damage during Rebif treatment, tell your doctor right away. They’ll order tests and may stop your Rebif treatment if you have liver injury. They’ll recommend other options for treating your condition.

Keeping track of side effects

During your Rebif treatment, consider taking notes on any side effects you’re having. You can then share this information with your doctor. This is especially helpful when you first start a new drug or combination of treatments.

Your side effect notes can include things such as:

  • what dose of the drug you were receiving when you had the side effect
  • how soon you had the side effect after starting that dose
  • what your symptoms were
  • how your symptoms affected your daily activities
  • what other medications you were taking
  • any other information you feel is important

Sharing notes with your doctor will help them learn more about how Rebif affects you. They can then use this information to adjust your treatment plan if needed.

Rebif can sometimes cause harmful effects in people with certain conditions. This is known as a drug-condition interaction. Other factors may also affect whether this drug is a good treatment option for you.

Talk with your doctor about your health history before starting Rebif. Be sure to tell them if any of the following factors apply to you:

  • liver problems
  • thyroid problems
  • seizures
  • depression or suicidal thoughts or behavior
  • bleeding problems
  • blood clots
  • allergy to albumin or mannitol
  • previous allergic reaction to Rebif
  • pregnancy
  • breastfeeding
  • alcohol consumption

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.