Betaseroninterferon beta-1b
According to the FDA label: BETASERON 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. BETASERON is an interferon beta indicated for the treatment of relapsing forms of multiple sclerosis, to include clinically isolated syndrome, relapsing-remitting disease, and active secondary progressive disease, in adults. ( 1 )
19,028 adverse event reports submitted to the FDA (2003–2026)
Top Reported Adverse Events
The most frequently reported events in association with Betaseron 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.
Show these terms with plain-language definitions
Tap any term below for a plain-language definition.
Influenza Like Illness 1,402 reports
A set of symptoms resembling the flu, such as fever, aches, and tiredness, without a confirmed flu diagnosis.
Full definition in the glossary →Multiple Sclerosis Relapse 1,343 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 →Injection Site Pain 1,199 reports
Pain at the spot on the body where a medication was injected.
Full definition in the glossary →Fatigue 1,194 reports
Extreme tiredness or lack of energy that does not improve with rest.
Full definition in the glossary → See all drugs reporting this event →Multiple Sclerosis 1,166 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 →Injection Site Erythema 978 reports
Redness of the skin at the spot where a medication was injected. Erythema means skin redness.
Full definition in the glossary →Drug Ineffective 963 reports
A report that the medication did not work as expected for the person taking it. This is a reporting category, not a sign the drug is defective. It simply means someone felt it was not helping their condition.
Full definition in the glossary →Pain 854 reports
A general report of physical discomfort, used when no more specific location is given.
Full definition in the glossary →Headache 844 reports
Pain in the head or upper neck.
Full definition in the glossary → See all drugs reporting this event →Injection Site Reaction 839 reports
A general report of a reaction at the spot where a medication was injected, such as redness, swelling, or pain.
Full definition in the glossary →Fall 817 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 →Depression 814 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 →Gait Disturbance 780 reports
Difficulty walking normally, such as an unsteady or altered way of walking.
Full definition in the glossary →Pyrexia 747 reports
The medical term for fever, meaning a raised body temperature.
Full definition in the glossary → See all drugs reporting this event →Death 726 reports
A report that the person died. A death appearing in reports for a drug does not mean the drug caused it. Reports record that a death occurred while the medication was being used, which can happen for many unrelated reasons.
Full definition in the glossary →
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 | 14,145 |
| Male | 4,104 |
| Unknown | 165 |
By Age Group
View age group data as a table
| Age group | Reports |
|---|---|
| 0-17 | 86 |
| 18-34 | 1,432 |
| 35-49 | 3,883 |
| 50-64 | 5,158 |
| 65-74 | 1,449 |
| 75+ | 273 |
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 Betaseron. 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 |
|---|---|
| Non-Serious | 8,374 |
| Other Serious | 6,794 |
| Hospitalization | 4,223 |
| Death | 1,335 |
| Disability | 251 |
| Life-Threatening | 130 |
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 Betaseron. 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 |
|---|---|
| 2003 | 1 |
| 2004 | 405 |
| 2005 | 535 |
| 2006 | 804 |
| 2007 | 1,200 |
| 2008 | 367 |
| 2009 | 502 |
| 2010 | 747 |
| 2011 | 1,162 |
| 2012 | 1,785 |
| 2013 | 1,656 |
| 2014 | 1,564 |
| 2015 | 1,381 |
| 2016 | 1,393 |
| 2017 | 1,291 |
| 2018 | 1,158 |
| 2019 | 986 |
| 2020 | 583 |
| 2021 | 400 |
| 2022 | 352 |
| 2023 | 322 |
| 2024 | 197 |
| 2025 | 176 |
| 2026 (partial) | 61 |
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 Betaseron
In FDA adverse event reports that mention Betaseron, these medications appeared most often in the same report.
- Dalfampridine (1,232 reports)
- Baclofen (1,191 reports)
- Gabapentin (980 reports)
- Ergocalciferol (883 reports)
- Interferon Beta-1a (865 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