DIMETHYL FUMARATE

55/100 · Moderate

Manufactured by Biogen Inc.

Dimethyl Fumurate Adverse Events: Common Mild Reactions with Some Serious Cases

232,901 FDA adverse event reports analyzed

Last updated: 2026-05-12

About DIMETHYL FUMARATE

DIMETHYL FUMARATE is a medication tracked in the FDA Adverse Event Reporting System (FAERS), manufactured by Biogen Inc.. Based on analysis of 232,901 FDA adverse event reports, DIMETHYL FUMARATE has a safety score of 55 out of 100. This moderate score indicates a notable volume of adverse event reports that patients and providers should be aware of. The most commonly reported adverse reactions for DIMETHYL FUMARATE include FLUSHING, NAUSEA, DIARRHOEA, MULTIPLE SCLEROSIS RELAPSE, FATIGUE. This page provides a comprehensive breakdown of reported side effects, safety signals, patient demographics, and AI-powered safety analysis for DIMETHYL FUMARATE.

AI Safety Analysis

Dimethyl Fumarate has a safety concern score of 55 out of 100, placing it in the elevated concern category based on analysis of FDA adverse event data. The FDA has received approximately 232,901 adverse event reports for this medication, which is primarily manufactured by Biogen Inc..

The most commonly reported adverse events include Flushing, Nausea, Diarrhoea. Of classified reports, 33.2% were designated as serious by the FDA, meaning they involved hospitalization, disability, or other significant medical outcomes. The most common reactions are flushing, nausea, and diarrhea, which are generally mild to moderate.

Serious adverse events, including falls and seizures, account for about 33% of reports. The majority of reactions are non-serious, but the diversity of reactions indicates a complex safety profile.

Patients taking Dimethyl Fumarate should monitor for the commonly reported side effects and contact their healthcare provider if they experience any unusual symptoms. Dimethyl fumarate can cause falls and seizures, and patients should be monitored for these symptoms, especially in elderly patients. This analysis is based on voluntary FDA adverse event reports and should not replace professional medical advice.

Safety Score: 55/100

Dimethyl Fumarate received a safety concern score of 55/100 (elevated concern). This is based on a 33.2% serious event ratio across 121,679 classified reports. The score accounts for 232,901 total adverse event reports and 100 distinct reaction types. This elevated score indicates a notable proportion of serious adverse events and warrants careful monitoring.

Top Adverse Reactions

FLUSHING17,057 reports
NAUSEA8,956 reports
DIARRHOEA8,268 reports
MULTIPLE SCLEROSIS RELAPSE8,068 reports
FATIGUE6,937 reports
MULTIPLE SCLEROSIS5,704 reports
VOMITING5,643 reports
MEMORY IMPAIRMENT5,557 reports
GASTRIC DISORDER5,551 reports
ABDOMINAL PAIN UPPER5,397 reports
DRUG INEFFECTIVE5,193 reports
PRURITUS5,055 reports
HEADACHE5,032 reports
FALL5,015 reports
GAIT DISTURBANCE4,620 reports
MALAISE4,122 reports
ABDOMINAL DISCOMFORT3,614 reports
PAIN3,385 reports
DIZZINESS3,372 reports
ASTHENIA3,322 reports
HYPOAESTHESIA2,943 reports
BALANCE DISORDER2,770 reports
HOT FLUSH2,631 reports
PARAESTHESIA2,626 reports
RASH2,512 reports
ALOPECIA2,361 reports
URINARY TRACT INFECTION2,351 reports
GASTROINTESTINAL DISORDER2,248 reports
ABDOMINAL PAIN2,241 reports
DEPRESSION2,139 reports
MUSCLE SPASMS2,124 reports
ERYTHEMA2,123 reports
PAIN IN EXTREMITY2,009 reports
MUSCULAR WEAKNESS1,989 reports
MOBILITY DECREASED1,911 reports
FEELING ABNORMAL1,882 reports
DRUG DOSE OMISSION1,846 reports
CONSTIPATION1,840 reports
DYSPEPSIA1,800 reports
BURNING SENSATION1,770 reports
WHITE BLOOD CELL COUNT DECREASED1,762 reports
INSOMNIA1,743 reports
WEIGHT DECREASED1,725 reports
PRESCRIBED UNDERDOSE1,719 reports
URTICARIA1,710 reports
ANXIETY1,631 reports
COGNITIVE DISORDER1,630 reports
FEELING HOT1,601 reports
SEIZURE1,568 reports
VISUAL IMPAIRMENT1,554 reports
PYREXIA1,550 reports
CONFUSIONAL STATE1,547 reports
BACK PAIN1,533 reports
NASOPHARYNGITIS1,518 reports
STRESS1,489 reports
ABDOMINAL DISTENSION1,471 reports
DRUG INTOLERANCE1,443 reports
HYPERSENSITIVITY1,428 reports
DECREASED APPETITE1,390 reports
DEATH1,371 reports
DYSPNOEA1,360 reports
CENTRAL NERVOUS SYSTEM LESION1,358 reports
PRODUCT DOSE OMISSION ISSUE1,311 reports
TREMOR1,306 reports
PRODUCT DOSE OMISSION1,286 reports
UNDERDOSE1,275 reports
PNEUMONIA1,270 reports
ARTHRALGIA1,200 reports
GENERAL SYMPTOM1,156 reports
MATERNAL EXPOSURE DURING PREGNANCY1,092 reports
WEIGHT INCREASED1,091 reports
DEHYDRATION1,073 reports
LYMPHOCYTE COUNT DECREASED1,063 reports
INFLUENZA1,048 reports
INFLUENZA LIKE ILLNESS999 reports
FLATULENCE971 reports
MIGRAINE909 reports
VISION BLURRED907 reports
OFF LABEL USE901 reports
AMNESIA885 reports
HYPERHIDROSIS879 reports
COUGH870 reports
MUSCULOSKELETAL DISORDER839 reports
THERAPY CESSATION834 reports
CHEST PAIN817 reports
HERPES ZOSTER800 reports
GASTROOESOPHAGEAL REFLUX DISEASE794 reports
CONDITION AGGRAVATED790 reports
MUSCULOSKELETAL STIFFNESS762 reports
ADVERSE EVENT758 reports
SOMNOLENCE736 reports
PERIPHERAL SWELLING724 reports
SPEECH DISORDER714 reports
HYPERTENSION709 reports
CEREBROVASCULAR ACCIDENT708 reports
CHILLS698 reports
COVID 19667 reports
RHINORRHOEA667 reports
ADVERSE DRUG REACTION662 reports
ADVERSE REACTION645 reports

Key Safety Signals

  • Falls and seizures are key safety signals, indicating potential neurological risks.
  • Decreased white blood cell count and lymphocyte count are also notable, suggesting potential immunosuppressive effects.

Patient Demographics

Adverse event reports by sex: Female: 90,106, Male: 24,405, Unknown: 477. The most frequently reported age groups are age 53 (1,900 reports), age 51 (1,889 reports), age 52 (1,887 reports). These demographics reflect reporting patterns and may not represent the full patient population.

Report Outcomes

Out of 121,679 classified reports for DIMETHYL FUMARATE:

  • Serious: 40,367 reports (33.2%) — includes hospitalization, disability, life-threatening events, or death
  • Non-Serious: 81,312 reports (66.8%)
Serious 33.2%Non-Serious 66.8%

The FDA classifies an adverse event as “serious” if it results in death, hospitalization, disability, congenital anomaly, or requires intervention to prevent permanent damage.

Demographics Breakdown

Reports by Sex

Female90,106 (78.4%)
Male24,405 (21.2%)
Unknown477 (0.4%)

Reports by Age

Age 531,900 reports
Age 511,889 reports
Age 521,887 reports
Age 551,879 reports
Age 501,843 reports
Age 481,823 reports
Age 561,823 reports
Age 581,766 reports
Age 491,759 reports
Age 541,755 reports
Age 571,747 reports
Age 471,722 reports
Age 591,642 reports
Age 441,624 reports
Age 451,585 reports
Age 461,501 reports
Age 601,490 reports
Age 431,462 reports
Age 421,453 reports
Age 611,414 reports

Demographics reflect voluntary FDA adverse event reporting patterns and may not represent the full patient population.

Drug Interactions & Warnings

Dimethyl fumarate can cause falls and seizures, and patients should be monitored for these symptoms, especially in elderly patients.

What You Should Know

If you are taking Dimethyl Fumarate, here are important things to know. The most commonly reported side effects include flushing, nausea, diarrhoea, multiple sclerosis relapse, fatigue. While many of these may be mild and temporary, you should contact your healthcare provider if any symptoms are severe or persistent. Patients should report any unusual symptoms to their healthcare provider immediately. Follow prescribed dosing instructions carefully to minimize the risk of adverse reactions. If you experience a serious adverse reaction, seek emergency medical attention immediately or call 911. You can report side effects to the FDA's MedWatch program at 1-800-FDA-1088.

Regulatory Context

The FDA continues to monitor the safety of dimethyl fumarate, and updates will be provided as necessary.

Frequently Asked Questions

How many adverse event reports has the FDA received for Dimethyl Fumarate?

The FDA has received approximately 232,901 adverse event reports associated with Dimethyl Fumarate. These reports come from healthcare professionals, consumers, and manufacturers through the FDA Adverse Event Reporting System (FAERS). Note that the number of reports does not directly indicate the frequency of side effects, as adverse events are voluntarily reported and may be underrepresented.

What are the most commonly reported side effects of Dimethyl Fumarate?

The most frequently reported adverse events for Dimethyl Fumarate include Flushing, Nausea, Diarrhoea, Multiple Sclerosis Relapse, Fatigue. By volume, the top reported reactions are: Flushing (17,057 reports), Nausea (8,956 reports), Diarrhoea (8,268 reports). These figures reflect FDA adverse event reports and may not represent the true incidence rate of these side effects in all patients taking Dimethyl Fumarate.

What percentage of Dimethyl Fumarate adverse event reports are serious?

Out of 121,679 classified reports, 40,367 (33.2%) were classified as serious and 81,312 as non-serious. The FDA classifies an event as "serious" if it results in death, hospitalization, disability, or other medically significant outcomes. A higher serious-event ratio warrants closer attention but does not necessarily mean the drug is unsafe.

Who reports adverse events for Dimethyl Fumarate (by sex)?

Adverse event reports for Dimethyl Fumarate break down by patient sex as follows: Female: 90,106, Male: 24,405, Unknown: 477. This distribution reflects reporting patterns rather than actual risk differences between groups. Reporting rates can be influenced by prescribing patterns, disease demographics, and reporting behavior.

What age groups report the most side effects for Dimethyl Fumarate?

The most frequently reported age groups for Dimethyl Fumarate adverse events are: age 53: 1,900 reports, age 51: 1,889 reports, age 52: 1,887 reports, age 55: 1,879 reports, age 50: 1,843 reports. Age-related reporting patterns can reflect both the demographics of the patient population and potential age-related susceptibility to certain side effects.

Who manufactures Dimethyl Fumarate?

The primary manufacturer associated with Dimethyl Fumarate adverse event reports is Biogen Inc.. Multiple manufacturers may produce generic versions of this drug. The manufacturer listed reflects the most frequently reported brand in FDA adverse event data.

What other side effects have been reported for Dimethyl Fumarate?

Beyond the most common reactions, other reported adverse events for Dimethyl Fumarate include: Multiple Sclerosis, Vomiting, Memory Impairment, Gastric Disorder, Abdominal Pain Upper. Less common side effects can still be clinically significant. Patients should report any unusual symptoms to their healthcare provider.

How do I report a side effect from Dimethyl Fumarate?

You can report adverse events from Dimethyl Fumarate to the FDA through their MedWatch program at www.fda.gov/medwatch, by calling 1-800-FDA-1088, or by completing Form FDA 3500. Healthcare professionals, consumers, and manufacturers can all submit reports. Reporting helps the FDA monitor drug safety after approval.

What is Dimethyl Fumarate's safety score and what does it mean?

Dimethyl Fumarate has a safety concern score of 55 out of 100 (elevated concern). This score is calculated from the ratio of serious to non-serious adverse events, the diversity of reported reactions, and the overall volume of reports relative to usage. The most common reactions are flushing, nausea, and diarrhea, which are generally mild to moderate.

What are the key safety signals for Dimethyl Fumarate?

Key safety signals identified in Dimethyl Fumarate's adverse event data include: Falls and seizures are key safety signals, indicating potential neurological risks.. Decreased white blood cell count and lymphocyte count are also notable, suggesting potential immunosuppressive effects.. These signals are derived from patterns in FDA reports and should be discussed with a healthcare provider for personalized assessment.

Does Dimethyl Fumarate interact with other drugs?

Dimethyl fumarate can cause falls and seizures, and patients should be monitored for these symptoms, especially in elderly patients. Always inform your healthcare provider about all medications, supplements, and over-the-counter drugs you are taking before starting Dimethyl Fumarate.

What should patients know before taking Dimethyl Fumarate?

Patients should report any unusual symptoms to their healthcare provider immediately. Follow prescribed dosing instructions carefully to minimize the risk of adverse reactions.

Are Dimethyl Fumarate side effects well-documented?

Dimethyl Fumarate has 232,901 adverse event reports on file with the FDA. Serious adverse events, including falls and seizures, account for about 33% of reports. The volume of reports for Dimethyl Fumarate reflects both the drug's usage level and the vigilance of the reporting community.

What is the FDA's position on Dimethyl Fumarate?

The FDA continues to monitor the safety of dimethyl fumarate, and updates will be provided as necessary. For the most current regulatory information, check the FDA's drug labeling database or consult your pharmacist.

Other Drugs by Biogen Inc.

Explore other medications manufactured by Biogen Inc. and compare their safety profiles:

DIROXIMEL FUMARATE (65/100)INTERFERON BETA 1A (72/100)NATALIZUMAB (72/100)Tecfidera

View all Biogen Inc. drugs →

Related Drugs

Drugs related to DIMETHYL FUMARATE based on therapeutic use, drug class, or shared indications:

WarfarinIbuprofenAmoxicillin
Important Disclaimer: This content is generated by AI analysis of FDA adverse event reports and is provided for informational purposes only. It is not medical advice. Adverse event reports submitted to the FDA do not prove that a medication caused the reported side effect. Always consult your healthcare provider before starting, stopping, or changing any medication. If you experience a serious side effect, contact your doctor or call 911 immediately.