Possible side effects

Before you choose a treatment for relapsing MS, you should consider possible side effects. Rebif® (interferon beta-1a) does have potential side effects. Some are common and others can be potentially serious and require immediate medical attention.

Please talk to your health care provider about any side effects you may have.

Please see important safety information below and the Rebif Medication Guide and Prescribing Information in the top of this website, and speak with your health care provider for more information.

What are the possible side effects of Rebif?

Flu-like symptoms

Most patients have flu-like symptoms such as fever, chills, sweating, muscle aches and tiredness. For many patients, these symptoms will lessen or go away over time. You should talk to your doctor about whether you should take an over the counter medication for pain or fever reduction before or after taking your dose of Rebif.

Learn tips that may help with flu-like symptoms from an MS neurologist

Injection-site reactions

Redness, pain or swelling may occur at the place of injection. Some patients have developed skin infections or areas of severe skin damage (necrosis) requiring treatment by a doctor. If one of your injection sites becomes swollen and painful or the area looks infected and it doesn't heal within a few days, you should call your doctor.

Depression and anxiety

Some patients taking interferons have become very depressed and/or anxious. There have been patients taking interferons who have had thoughts about killing themselves. Depression is not uncommon in people with multiple sclerosis. However, if you are feeling noticeably sadder or helpless, or feel like hurting yourself or others, you should tell a family member or friend right away and call your doctor as soon as possible.

Liver problems

Your liver function may be affected. Your health care provider may ask you to have regular blood tests to make sure that your liver is working properly. If you have had liver disease before and/or develop symptoms of changes in your liver, including yellowing of the skin and whites of the eyes and easy bruising, you should call your doctor immediately.

Blood problems

You may have a drop in the levels of infection-fighting blood cells, red blood cells or cells that help to form blood clots. If the drop in levels is severe, it can lessen your ability to fight infections, make you feel tired or sluggish, or cause you to bruise or bleed easily.

Thyroid problems

Your thyroid function may change. Symptoms of changes in the function of your thyroid include feeling cold or hot all the time, or a change in your weight (gain or loss) without a change in your diet or amount of exercise.

Allergic reactions

Some people have had hives, rash, skin bumps or itching while they were taking Rebif. Other people have had more serious allergic reactions, such as difficulty breathing or feeling light-headed. Allergic reactions can happen after your first dose or may not happen until after you have taken Rebif many times. Less severe allergic reactions such as itching, flushing or skin bumps can also happen at any time. You should tell your health care provider if you think you are having an allergic reaction.

Have questions about certain side effects with Rebif?

The trained MS LifeLines Nurse Network can help. The MS LifeLines Nurse Network is a vast team of nurses who provide training and support to individuals with relapsing MS. MS-certified nurses provide education to patients and families about MS and tips for people taking Rebif.

Injection-site reactions and flu-like symptoms (fever, chills, sweating, muscle aches and tiredness) are the most common side effects of Rebif. But there may be things you can do to help with these side effects.

Get helpful tips for managing common symptoms and certain side effects should they occur by speaking to an MS LifeLines Nurse at 1-877-447-3243 Monday through Friday 8 AM to 10 PM ET and Saturday and Sunday 9 AM to 5 PM ET.

For more information about drug safety and adverse event reporting, visit the Food and Drug Administration website.

Ron B.
MS LifeLines Ambassador, living with relapsing MS