Pronunciation: re-bif
Generic name: interferon beta-1a
Brand names: Rebif, Rebif Rebidose
Dosage form: single-dose prefilled syringe for subcutaneous use, single-dose prefilled autoinjector for subcutaneous use
Drug class: Interferons

Medically reviewed by Carmen Pope, BPharm. Last updated on Jan 2, 2025.

What is Rebif?

Rebif is used to treat relapsing forms of multiple sclerosis (MS) in adults, including clinically isolated syndrome, relapsing-remitting disease, and active secondary progressive disease.

• The generic name for Rebif is interferon beta-1a.
• Rebif is injected under the skin (subcutaneously), usually 3 times a week, such as on a Monday, Wednesday, and Friday.

Rebif’s mechanism of action resembles that of interferons which are proteins naturally produced by our immune system that help regulate the body’s immune response and fight viral infections. Rebif is a man-made form of interferon that works in the same way, binding to specific receptors on cell surfaces and decreasing the activity of immune cells that attack the myelin sheath, reducing inflammation in the central nervous system, and helping to suppress the autoimmune response that characterizes MS.

Rebif belongs to the drug class called interferons. It may also be called an immunomodulator. Rebif will not cure MS, it will only decrease the frequency of relapse symptoms.

Rebif gained FDA approval on March 7, 2002. Another brand of interferon beta-1a given intramuscularly (into a muscle) called Avonex, was the first interferon beta-1a to be approved (May 17, 1996). There is no Rebif generic.

Rebif side effects

The most common side effects of Rebif are:

• flu-like symptoms such as:
  • muscle aches
  • fever
  • tiredness
  • chills.
• stomach pain
• changes in your liver tests.

Serious side effects and warnings

Rebif can cause the following serious side effects.

Behavioral health problems including depression and suicidal thoughts. You may have mood problems while taking Rebif, for example, depression (feeling hopeless or feeling bad about yourself), or thoughts of hurting yourself or suicide. Contact your healthcare provider immediately.

Liver problems or liver failure has been reported in people taking Rebif. Contact your healthcare provider immediately if you develop any of the following symptoms:

• nausea
• loss of appetite
• tiredness
• dark-colored urine and pale stools
• yellowing of your skin or the white part of your eye
• bleeding more easily than normal
• confusion
• sleepiness.

Rebif may cause serious allergic and skin reactions. Contact your healthcare provider or seek emergency medical attention if you develop any of the following symptoms:

• itching
• swelling of your face, eyes, lips, tongue or throat
• trouble breathing
• anxiousness
• feeling faint
• skin rash, hives, sores in your mouth, or skin blisters and peels.

Injection site problems. Rebif may cause redness, pain, itching, or swelling at the place where your injection was given. Call your healthcare provider immediately if an injection site becomes swollen and painful or the area looks infected. You may have a skin infection or an area of severe skin damage (necrosis) requiring treatment by a healthcare provider.

Blood problems. Rebif can affect your bone marrow and cause low red and white blood cell, and platelet counts. In some people, these blood cell counts may fall to dangerously low levels. If your blood cell counts become very low, you can get infections and problems with bleeding and bruising. Your healthcare provider may ask you to have regular blood tests to check for blood problems.

Pulmonary arterial hypertension. Pulmonary arterial hypertension (high blood pressure in the arteries of the lungs) can occur with interferon beta products, including Rebif. Symptoms may include new fatigue or shortness of breath. Contact your healthcare provider right away if you develop these symptoms.

Thrombotic microangiopathy (TMA). TMA is a condition that involves injury to the smallest blood vessels in your body and this has been reported with Rebif. TMA can also cause injury to your red blood cells (the cells that carry oxygen to your organs and tissues) and your platelets (cells that help your blood clot) and can sometimes lead to death. Your healthcare provider may tell you to stop taking Rebif if you develop TMA.

Seizures. Some people have had seizures while taking Rebif.

Autoimmune diseases. Problems with easy bleeding or bruising (idiopathic thrombocytopenia), thyroid gland problems (hyperthyroidism and hypothyroidism), and autoimmune hepatitis have happened in some people who use Rebif.

Eye Disorders: Retinal disorders (such as retinopathy, cotton wool spots, or obstruction of
the retinal artery or vein) have been reported with Rebif. See your healthcare provider immediately if you have any changes in your vision or eye pain.

During your treatment with Rebif see your healthcare provider regularly and have regular blood tests to check for side effects.

Tell your healthcare provider if you have any side effect that bothers you or does not go away. These are not all the possible side effects of Rebif. For more information, ask your healthcare provider or pharmacist. Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Related/similar drugs

Before taking

Do not take Rebif if you are allergic to interferon beta-1a, human albumin, Rebif, Avonex, or any inactive ingredients in the injection (see below for a list of inactive ingredients).

Before you take Rebif, tell your healthcare provider if you have or have had any of the following conditions:

• mental illness, including depression and suicidal behavior
• liver problems
• bleeding problems or blood clots
• low blood cell counts
• seizures (epilepsy)
• thyroid problems
• drink alcohol
• you are pregnant or plan to become pregnant
• you are breastfeeding or plan to breastfeed.

Pregnancy

It is not known if Rebif can harm your unborn baby.

Breastfeeding

Rebif may pass into your breast milk. Talk with your healthcare provider about the best way to feed your baby while taking this medicine.

How should I use Rebif?

See the Instructions for Use that come with the Rebif Package Insert.

• Your healthcare provider should show you how to prepare, measure, and inject your dose of Rebif before you use it for the first time.

How to inject Rebif for subcutaneous use

Rebif is given by injection under the skin (subcutaneous injection) on the same 3 days a week, for example, Monday, Wednesday, and Friday.

• Your injections should be at least 48 hours apart.
• Try to inject Rebif at the same time the three days that you have chosen to inject it (for example, always around 10am on Monday, Wednesday, and Friday).
• The best sites for giving yourself an injection are those areas with a layer of fat between the skin and muscle, like your thigh, the outer surface of your upper arm, your stomach or buttocks.
  • Do not use the area near your waistline or within 2 inches of your navel. If you are very thin, use only the thigh or outer surface of the arm for the injection.
• Inject Rebif exactly as your healthcare provider tells you.

Your healthcare provider will tell you how much Rebif to inject and may change the dose based on how your body responds. 

• Do not change your dose unless your healthcare provider tells you to.
• Change (rotate) the injection site you choose with each injection. This will help decrease the chance that you will have an injection site reaction.
• Do not inject Rebif into an area of the body where the skin is irritated, reddened, bruised, infected, or scarred in any way.

Rebif comes as a:

• prefilled syringe
• single-use prefilled autoinjector (Rebif Rebidose).

Your healthcare provider will decide which is best for you. Always use a new, unopened, prefilled syringe or autoinjector for each injection. Do not reuse prefilled syringes or autoinjectors.

See the Rebif Package Insert for complete administration instructions.

Rebif dosing information

The recommended dose of Rebif for MS is either 22 micrograms or 44 micrograms injected subcutaneously, 3 times a week.

Titration: Generally, the starting dose should be 20% of the prescribed dose three times per week, and increased over 4 weeks to the targeted recommended dose of either 22 micrograms or 44 micrograms injected subcutaneously three times per week. Your healthcare provider will calculate this dose for you.

Pain and/or fever-relieving medicines on treatment days may help reduce side effects such as flu-like symptoms.

See the Rebif Prescribing Information for full dosing instructions.

What other drugs will affect Rebif?

Tell your healthcare provider about all medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements.

Rebif and other medicines may affect each other causing side effects. Ask your healthcare provider or pharmacist for a list of these medicines, if you are not sure.

Know the medicines you take. Keep a list of them to show your healthcare provider and pharmacist when you get a new medicine.

Storage

Store Rebif in the refrigerator between 36°F to 46°F (2°C to 8°C).

Do not freeze Rebif.

If you cannot refrigerate your Rebif pen or autoinjector, you can store it at temperatures above 36°F and below 77°F (2°C to 25°C) for up to 30 days.

Keep Rebif away from heat and light.

Rebif ingredients

Active ingredient: Rebif

Inactive ingredients: albumin (human), mannitol, sodium acetate, water for injection

Single-dose Rebif prefilled syringe is available as 8.8 mcg in 0.2 mL, and 22 mcg or 44 mcg in 0.5 mL.

Single-dose Rebif autoinjector is available as 8.8 mcg in 0.2 mL, and 22 mcg or 44 mcg in 0.5 mL.

Who makes Rebif?

EMD Serono Inc. makes Rebif.

Rebif Biosimilars

Biosimilar and interchangeable products are biological products that are highly similar to and have no clinically meaningful differences from the reference product.

Reference products

These are biological products that have already been approved by the FDA, against which biosimilar products are compared. There are 2 for Rebif.

Popular FAQ

More FAQ

• How and where do you inject Rebif?
• What is Rebif used for and how does it work?
• Does Rebif suppress the immune system?

View more FAQ

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Medical Disclaimer