Rebifinterferon beta-1a
According to the FDA label: REBIF is indicated for the treatment of relapsing forms of multiple sclerosis (MS), to include clinically isolated syndrome, relapsing-remitting disease, and active secondary progressive disease, in adults. Rebif is an interferon beta indicated for the treatment of relapsing forms of multiple sclerosis (MS), to include clinically isolated syndrome, relapsing-remitting disease, and active secondary progressive disease, in adults. ( 1 )
47,244 adverse event reports submitted to the FDA (2004–2026)
Top Reported Adverse Events
The most frequently reported events in association with Rebif in the FAERS database. These are events reported by patients taking this medication, not necessarily caused by it. A single report may include multiple events.
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Multiple Sclerosis Relapse 4,055 reports
A return or worsening of multiple sclerosis symptoms. It often appears in reports as part of the condition being treated.
Full definition in the glossary →Fatigue 2,966 reports
Extreme tiredness or lack of energy that does not improve with rest.
Full definition in the glossary → See all drugs reporting this event →Injection Site Erythema 2,937 reports
Redness of the skin at the spot where a medication was injected. Erythema means skin redness.
Full definition in the glossary →Influenza Like Illness 2,889 reports
A set of symptoms resembling the flu, such as fever, aches, and tiredness, without a confirmed flu diagnosis.
Full definition in the glossary →Fall 2,534 reports
A report that the person fell down. Falls are tracked because they can signal issues like dizziness, weakness, or balance problems.
Full definition in the glossary →Headache 2,423 reports
Pain in the head or upper neck.
Full definition in the glossary → See all drugs reporting this event →Injection Site Pain 2,403 reports
Pain at the spot on the body where a medication was injected.
Full definition in the glossary →Pain 1,918 reports
A general report of physical discomfort, used when no more specific location is given.
Full definition in the glossary →Depression 1,828 reports
A persistent low mood, loss of interest, or feelings of sadness. If you are struggling, the 988 Suicide and Crisis Lifeline (call or text 988 in the US) is available 24 hours a day.
Full definition in the glossary → See all drugs reporting this event →Multiple Sclerosis 1,767 reports
A condition where the immune system affects the protective covering of nerves, which can disrupt movement and other functions. It often appears in reports as a condition being treated.
Full definition in the glossary →Gait Disturbance 1,751 reports
Difficulty walking normally, such as an unsteady or altered way of walking.
Full definition in the glossary →Hypoaesthesia 1,643 reports
Reduced sense of touch or numbness in part of the body. Also spelled hypoesthesia in American English.
Full definition in the glossary → See all drugs reporting this event →Asthenia 1,569 reports
Physical weakness or lack of strength.
Full definition in the glossary →Urinary Tract Infection 1,564 reports
An infection in the bladder, urethra, or kidneys, often called a UTI.
Full definition in the glossary → See all drugs reporting this event →Nausea 1,434 reports
The feeling of sickness in your stomach that often comes before vomiting.
Full definition in the glossary → See all drugs reporting this event →
Ranked by frequency of reports, not severity. The most-reported event is not necessarily the most dangerous or the most common in patients taking this drug.
Who Is Reporting
Demographics of patients in FAERS reports that included this information. Not all reports include patient demographics.
By Sex
View reporter sex data as a table
| Sex | Reports |
|---|---|
| Female | 35,989 |
| Male | 10,174 |
| Unknown | 253 |
By Age Group
View age group data as a table
| Age group | Reports |
|---|---|
| 0-17 | 337 |
| 18-34 | 4,550 |
| 35-49 | 9,417 |
| 50-64 | 9,258 |
| 65-74 | 1,865 |
| 75+ | 255 |
This shows who filed reports, reflecting who takes this drug and who tends to report, not who is at greatest risk.
Reported Outcomes
Outcomes recorded in FAERS reports that included Rebif. A single report may involve multiple reactions, each with a different outcome. These categories are defined by FDA reporting guidelines, not by PillSignal.
View outcome data as a table
| Outcome | Reports |
|---|---|
| Other Serious | 20,199 |
| Hospitalization | 17,058 |
| Non-Serious | 10,706 |
| Death | 2,781 |
| Disability | 1,091 |
| Life-Threatening | 881 |
Serious outcomes are far more likely to be reported than mild ones, so this overstates how often outcomes are serious. A recorded death does not mean the drug caused it.
Report Volume Over Time
Number of FAERS reports received per quarter for Rebif. Changes in volume may reflect shifts in prescribing rates, media attention, or reporting behavior, not changes in the medication's safety profile.
View report trend as a table
| Year | Reports |
|---|---|
| 2004 | 314 |
| 2005 | 1,651 |
| 2006 | 571 |
| 2007 | 1,652 |
| 2008 | 2,032 |
| 2009 | 2,505 |
| 2010 | 3,612 |
| 2011 | 4,468 |
| 2012 | 4,809 |
| 2013 | 5,830 |
| 2014 | 3,077 |
| 2015 | 1,884 |
| 2016 | 1,763 |
| 2017 | 1,907 |
| 2018 | 1,899 |
| 2019 | 1,858 |
| 2020 | 1,461 |
| 2021 | 1,758 |
| 2022 | 1,591 |
| 2023 | 1,039 |
| 2024 | 785 |
| 2025 | 629 |
| 2026 (partial) | 149 |
The steep increase around 2004 reflects the FDA's move to electronic submission, not a change in this drug's safety. Trends track reporting volume, not risk.
Medications commonly reported with Rebif
In FDA adverse event reports that mention Rebif, these medications appeared most often in the same report.
- Baclofen (2,525 reports)
- Gabapentin (2,353 reports)
- Dalfampridine (2,225 reports)
- Ibuprofen (1,812 reports)
- Ergocalciferol (1,673 reports)
This reflects co-occurrence in submitted reports, not evidence of drug interaction or combined risk. People often report several medications taken for the same condition or for unrelated reasons. Talk to a doctor or pharmacist about your specific medications.
Related Drugs
Other medications with similar adverse event profiles in FDA FAERS reports.
Data Source
This data is sourced from the FDA's Adverse Event Monitoring System (AEMS), formerly FAERS, via the OpenFDA API. PillSignal is not affiliated with the FDA.
View this data on the FDA website →Data last updated: June 2026