Reported Reactions

Drugs

Brand name · Dimethyl fumarate

Tecfidera: adverse event reports filed with FDA

114,022 reports list it as a suspect or interacting product, 2010–2026.

114,022
reports as suspect product
0.6% of all reports · about 7,319 a year
711
reports, 12 months to June 2026
1,213 in the 12 months before
32.6%
marked serious by the reporter
57.4% across all reports
1.8%
record death among outcomes, as reported
2,007 reports · not verified by FDA

114,022 adverse event reports received by FDA list the brand name Tecfidera (dimethyl fumarate) as a suspect or interacting product, from December 2010 to June 2026. A further 5,069 reports list it only as a concomitant medication, and those are not counted in the figures on this page.

In the 12 months to June 2026, 711 reports listed it, down 41% from 1,213 in the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. Over its reporting history that is about 7,319 reports a year and 0.6% of the 20,646,523 reports in the database. How many people take it is not in the data, so a count is not a rate of occurrence.

Reporters most often recorded flushing (14.5%), nausea (7.5%) and diarrhoea (6.9%). A report can list several reactions, so shares add to more than 100%; 2,729 different terms appear across these reports. Flushing is recorded in 14.5% of these reports, against 0.5% of all reports in the database.

32.6% of the reports are marked serious by the reporter; 1.8% record death among the outcomes and 18.7% record hospitalisation, as reported. 78% of the reports came from consumers, and the largest patient age group is 45 to 64 (26.9%). FDA states that "a causal relationship cannot be established between product and reactions listed in a report" and that for any given report "there is no certainty that a suspected drug caused the event."

Reports by month, five years

0304608Jul 2021: 399Aug 2021: 454Sep 2021: 394Oct 2021: 339Nov 2021: 404Dec 2021: 3422022Jan 2022: 511Feb 2022: 608Mar 2022: 430Apr 2022: 328May 2022: 370Jun 2022: 355Jul 2022: 302Aug 2022: 342Sep 2022: 305Oct 2022: 231Nov 2022: 238Dec 2022: 2582023Jan 2023: 260Feb 2023: 332Mar 2023: 298Apr 2023: 219May 2023: 234Jun 2023: 227Jul 2023: 159Aug 2023: 195Sep 2023: 182Oct 2023: 136Nov 2023: 125Dec 2023: 1372024Jan 2024: 131Feb 2024: 135Mar 2024: 140Apr 2024: 137May 2024: 92Jun 2024: 115Jul 2024: 100Aug 2024: 104Sep 2024: 84Oct 2024: 107Nov 2024: 104Dec 2024: 832025Jan 2025: 84Feb 2025: 115Mar 2025: 113Apr 2025: 122May 2025: 99Jun 2025: 98Jul 2025: 82Aug 2025: 60Sep 2025: 90Oct 2025: 50Nov 2025: 53Dec 2025: 452026Jan 2026: 39Feb 2026: 70Mar 2026: 76Apr 2026: 55May 2026: 47Jun 2026: 44

Reports by the month FDA received them. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases.

By year received

08,74717,4942010: 120102011: 12012: 420122013: 14,3402014: 17,49420142015: 12,0272016: 12,64020162017: 11,6062018: 11,59920182019: 10,1062020: 9,18820202021: 5,5602022: 4,27820222023: 2,5042024: 1,33220242025: 1,0112026: 3312026

2026 covers reports received through June 2026 only.

Reactions recorded in the reports

share of Tecfidera reports recording the termall reports in the database

  1. Flushingsudden reddening or warmth of the skin14.5%16,542
  2. Nauseafeeling sick7.5%8,585
  3. Diarrhoealoose or frequent stools6.9%7,914
  4. Multiple sclerosis relapsea flare of multiple sclerosis6.6%7,522
  5. Fatiguetiredness5.6%6,356
  6. Vomitingbeing sick4.8%5,429
  7. Memory impairmentmemory problems4.7%5,332
  8. Abdominal pain upperupper stomach pain4.6%5,235
  9. Pruritusitching4.2%4,823
  10. Headachehead pain4.1%4,649
  11. Falla fall3.9%4,409
  12. Drug ineffectivethe medicine did not work as expected3.8%4,306
  13. Gait disturbancedifficulty walking3.5%3,982
  14. Malaisegeneral feeling of being unwell3.5%3,945
  15. Abdominal discomfortstomach discomfort3.1%3,479
  16. Painpain, site not specified2.7%3,103
  17. Dizzinesslight-headedness or unsteadiness2.7%3,058
  18. Astheniaweakness or lack of energy2.6%2,969
  19. Hypoaesthesianumbness2.4%2,746
  20. Hot flusha hot flush2.2%2,535
  21. Balance disorderproblems with balance2.2%2,465
  22. Paraesthesiatingling or pins and needles2.1%2,415
  23. Rashskin rash2%2,323
  24. Alopeciahair loss1.9%2,200
  25. Abdominal painstomach or belly pain1.9%2,130
  26. Urinary tract infectionbladder or urinary infection1.8%2,093
  27. Erythemaskin redness1.8%2,013

Top 30 of 2,729 MedDRA preferred terms recorded across these reports, with a plain-language gloss where one is available. One report can record several terms. The hollow bar is the share of all reports in the database; it describes the reports, not the patients. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic."

Outcomes recorded

Death1.8%2,007
Life-threatening0.4%404
Hospitalisation (initial or prolonged)18.7%21,365
Disability0.3%332
Congenital anomaly0.1%109
Other serious13.9%15,868
Not serious67.4%76,830

Outcome flags as the reporter set them; a report can carry several, and "other serious" is FDA's own category for serious reports outside the named outcomes. Grey bar: all 20,646,523 reports. FDA has not verified any outcome and states that the reports "cannot be used to estimate the incidence of these events."

Patients and reporters

Patient age

Under 20.1%144
2 to 110%30
12 to 170.2%192
18 to 4417.2%19,594
45 to 6426.9%30,692
65 to 744.5%5,114
75 and over0.6%653
Age not given50.5%57,603

Patient sex

Female74.3%84,666
Male19.9%22,693
Not given5.8%6,663

Who reported

Physician11%12,568
Pharmacist2.6%2,989
Other health professional7.9%8,972
Lawyer0%8
Consumer or non-health professional78%88,923
Not given0.5%562

Age and sex as stated in the report; the reporter's qualification is the primary source recorded by FDA. 91.1% of reports give the United States as the country of the event or reporter.

Reason for use recorded

Indication as recorded (MedDRA)ReportsShare
Multiple sclerosis89,33278.3%
Relapsing-remitting multiple sclerosis4,4803.9%
Maternal exposure timing unspecified1950.2%
Secondary progressive multiple sclerosis780.1%
Relapsing multiple sclerosis680.1%
Paternal exposure timing unspecified150%

The indication field is filled in by the reporter and is often blank; shares are of all 114,022 reports.

Drugs most often listed in the same reports

Drug (any role in the report)ReportsShare of Tecfidera reports
Ampyra7,6936.7%
Baclofen5,3154.7%
Avonex4,7134.1%
Gabapentin4,3413.8%
Vitamin d3,8753.4%
Ergocalciferol3,2032.8%
Tysabri2,6152.3%
Aspirin2,5692.3%
Lisinopril1,8311.6%
Vitamin B121,6631.5%

Other products listed in reports where Tecfidera is a suspect product, whatever their own role. Co-listing means the two were recorded together; it says nothing about either product's part in the event. Only the 2,500 most-reported names are counted here.

In context

MeasureTecfideraAll reports
Reports as suspect product114,02220,646,523
Share of that pool—0.6%
Reports, latest 12 months7111,332,454
Marked serious32.6%57.4%
Death recorded among outcomes, per 1,000 reports1891
Hospitalisation recorded, per 1,000 reports187213
Consumer-filed share78%45.8%
Top term, share of reportsFlushing 14.5%0.5%

Shares are of reports, not of patients treated. The number of people taking a product is not in the data, so none of these figures is a rate, and differences between columns reflect who takes a product, who reports and how long it has been sold. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic."

Questions about Tecfidera reports

How many adverse event reports has FDA received for Tecfidera?

114,022 reports list Tecfidera as a suspect or interacting product in the openFDA FAERS release of 28 Sep 2026, covering reports received through June 2026. 711 of them arrived in the latest 12 months. Another 5,069 list it only as a concomitant medication.

What reactions are recorded in Tecfidera reports?

flushing (14.5%), nausea (7.5%), diarrhoea (6.9%), multiple sclerosis relapse (6.6%) and fatigue (5.6%). These are MedDRA preferred terms coded from what the reporter described; a report can list several, and a term's presence is not a finding that Tecfidera was responsible.

How serious are the reports?

32.6% are marked serious by the reporter. Among the outcomes recorded, 1.8% of reports include death and 18.7% include hospitalisation. FDA has not verified these outcomes and states that the reports "cannot be used to estimate the incidence" of the events.

Who files these reports?

consumer or non-health professional (78%), physician (11%) and other health professional (7.9%). Most reports reach FDA through the manufacturer, which must forward reports it receives.

Are reports for Tecfidera rising?

711 reports in the 12 months to June 2026, down 41% from 1,213 in the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. Counts also move with how many people take a product, its time on the market and publicity.

Do these reports show that Tecfidera was responsible for these reactions?

No. FDA states that "a causal relationship cannot be established between product and reactions listed in a report" and that for any given report "there is no certainty that a suspected drug caused the event." The reaction may relate to the condition being treated, to other medicines, or to something else.

Is this a list of the side effects of Tecfidera?

No. It is a count of what was reported to FDA. The adverse reactions observed in clinical studies are printed on the FDA-approved label, which a pharmacist or clinician can go through with you.

How do I report an adverse event?

Consumers and health professionals can report to FDA through MedWatch (Form FDA 3500 online, or 1-800-FDA-1088), or to the manufacturer, which must pass reports on. See the guide on how to report.

Where this comes from. Counts are built from the openFDA Drug Adverse Event (FAERS) bulk export released 28 Sep 2026, which holds reports FDA received through 30 Jun 2026. Drug names are as reported, resolved to the brand or generic name on the FDA label where openFDA's harmonisation matched them; classes are the pharmacologic class (EPC) from the label and the National Drug Code Directory of 17 Sep 2026. A report counts here when it lists Tecfidera as a suspect or interacting product; reports listing it only as a concomitant medication (5,069) are excluded. No report narrative, lot number, patient detail or reporter identity is published. See the methodology and sources; FDA's record is authoritative, and corrections are handled within five working days.

Drug data (FAERS) through 30 Jun 2026; device data (MAUDE) through 31 Aug 2026. Not medical advice.