Drug · FAERS side-effect profile with label screen
Dimethyl Fumarate Kit side effects: what 3,295 FDA adverse event reports show
Drug class
Not stated in label
Label matched
Dimethyl Fumarate Kit (Dimethyl Fumarate)
closest FDA label found for this product string; brand list suppressed because the label is a related product, not an exact match
Who reports
3,295 reports · 60% serious · 99 with death outcome · 75% female
openFDA FAERS counts, all years, deduplication not applied
Used for
Dimethyl fumarate delayed-release capsules are 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. Dimethy.
FDA label, Indications and Usage
What it is
Dimethyl Fumarate Delayed-Release Capsules contain dimethyl fumarate which is also known by its chemical name, dimethyl (E) butenedioate, (C 6 H 8 O 4 ). It has the following structure: Dimeth.
FDA label, Description section
Boxed warning
None in the current label
How to read this page. FAERS is a spontaneous-reporting system: counts are not incidence rates and a signal is not proof of causation.
Each reaction below is run through an automated screen — is the term in the FDA label (known), in the indications (the disease being treated), an administrative/coding term, or none of these (unlabeled)?
That screen is mechanical text matching, not a causality assessment. The 30 hand-written Bradford Hill assessments are on the causality assessment page. Not medical advice.
Causality screen of the 40 strongest signals
Labeled adverse reaction 5Labeled (related wording) 2Likely indication confounding 2Reporting / coding artifact 4Lab value / disease marker 1Not in label — unassessed 26
What the badges mean
- Labeled adverse reaction The exact term appears in the label's warnings or adverse-reactions sections: a known, expected effect. The FAERS signal confirms the label rather than discovering anything.
- Labeled (related wording) The label describes this effect under different wording (e.g. 'neutropenia' for 'neutrophil count decreased'). Treated as known.
- Likely indication confounding The term appears in the label's indications: reports probably describe the disease being treated (or its progression), not a drug effect. Classic confounding by indication.
- Reporting / coding artifact An administrative, monitoring or exposure term (product issue, off-label use, 'test normal', overdose...). Not a biological reaction; a high PRR here reflects how reports are coded.
- Lab value / disease marker A laboratory result, investigation or disease-activity marker (antibody positive, CRP abnormal, swollen joint count) not described in the label. These usually mirror the monitored disease or testing protocol rather than a drug effect; not screened further.
- Not in label — unassessed Not found in the label text, not an artifact pattern. This is a genuine candidate for a formal causality assessment (Bradford Hill / WHO-UMC); it has NOT had one here.
Strongest disproportionality signals
Flagged terms (PRR ≥ 2, χ² ≥ 4, n ≥ 10), ranked by PRR; infinite PRRs (no comparator reports) excluded. The EBGM column is a second, shrinkage-based estimate (MGPS) with its 5th percentile EB05 and the BCPNN IC025; a pair flagged by PRR alone is marked PRR-only and should be read as fragile. The strata column recomputes the PRR on serious reports only and flags pairs whose reports are unusually skewed by sex or come mostly from consumers rather than clinicians. 66 further terms are in the interactive explorer. Reaction links open the term's cross-drug page.
Show:
| Reaction | Reports | PRR 95% CI · ROR · χ²/p | EBGM EB05 · IC025 | Label screen | Serious-only & strata | Trial cross-check |
|---|---|---|---|---|---|---|
| Lymphopenia | 80 | 36.4 29.3–45.2ROR 37.3 · χ² 2,703 / p <1e-300 | 35.9 EB05 29.8 · IC025 +4.5 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 34.4 · 97% clinician | no trial data cached |
| Flushing | 326 | 20.4 18.4–22.6ROR 22.5 · χ² 5,996 / p <1e-300 | 20.3 EB05 18.5 · IC025 +4.1 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 18.8 | no trial data cached |
| Multiple sclerosis | 151 | 20.0 17.1–23.4ROR 21.0 · χ² 2,711 / p <1e-300 | 19.9 EB05 17.4 · IC025 +4.0 3/3 methods agree | Likely indication confounding term in indications | serious PRR 23.2 | no trial data cached |
| Multiple sclerosis relapse | 217 | 20.0 17.6–22.8ROR 21.4 · χ² 3,905 / p <1e-300 | 19.9 EB05 17.8 · IC025 +4.0 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious PRR 23.2 | no trial data cached |
| Central nervous system lesion | 37 | 17.1 12.4–23.5ROR 17.2 · χ² 542 / p 3e-120 | 16.8 EB05 12.7 · IC025 +3.3 3/3 methods agree | Not in label — unassessed | serious PRR 18.6 | no trial data cached |
| Muscle spasticity | 27 | 13.9 9.5–20.2ROR 14.0 · χ² 309 / p 1e-69 | 13.4 EB05 9.4 · IC025 +2.8 3/3 methods agree | Not in label — unassessed | serious PRR 13.3 | no trial data cached |
| Rebound effect | 23 | 12.9 8.6–19.4ROR 13.0 · χ² 241 / p 1e-54 | 12.3 EB05 8.2 · IC025 +2.7 3/3 methods agree | Not in label — unassessed | serious PRR 19.8 · 96% clinician | no trial data cached |
| Lymphocyte count decreased | 31 | 11.2 7.9–15.9ROR 11.3 · χ² 277 / p 2e-62 | 10.6 EB05 7.6 · IC025 +2.7 3/3 methods agree | Lab value / disease marker | serious PRR 10.9 · ♀ 48% (drug 75%) | no trial data cached |
| Therapy interrupted | 114 | 10.5 8.8–12.6ROR 10.9 · χ² 975 / p 2e-214 | 10.4 EB05 8.8 · IC025 +3.0 3/3 methods agree | Reporting / coding artifact | serious PRR 16.3 | no trial data cached |
| Ataxia | 19 | 10.2 6.5–15.9ROR 10.2 · χ² 148 / p 3e-34 | 9.1 EB05 5.8 · IC025 +2.3 3/3 methods agree | Not in label — unassessed | serious PRR 8.3 | no trial data cached |
| Product substitution issue | 87 | 9.6 7.8–11.9ROR 9.9 · χ² 665 / p 6e-147 | 9.4 EB05 7.8 · IC025 +2.8 3/3 methods agree | Reporting / coding artifact | serious PRR 10.5 | no trial data cached |
| Micturition urgency | 17 | 9.6 5.9–15.4ROR 9.6 · χ² 122 / p 1e-28 | 8.3 EB05 5.2 · IC025 +2.1 3/3 methods agree | Not in label — unassessed | serious PRR 13.3 | no trial data cached |
| Eosinophilia | 21 | 7.7 5.0–11.7ROR 7.7 · χ² 115 / p 4e-27 | 6.7 EB05 4.6 · IC025 +2.0 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 7.6 · 100% clinician | no trial data cached |
| Hemiparesis | 19 | 7.1 4.5–11.1ROR 7.1 · χ² 93 / p 2e-22 | 6.2 EB05 4.1 · IC025 +1.8 3/3 methods agree | Not in label — unassessed | serious PRR 6.2 | no trial data cached |
| Sensory disturbance | 17 | 6.7 4.2–10.8ROR 6.7 · χ² 77 / p 9e-19 | 5.8 EB05 3.8 · IC025 +1.7 3/3 methods agree | Not in label — unassessed | serious PRR 7.0 | no trial data cached |
| Therapy cessation | 48 | 6.0 4.5–7.9ROR 6.1 · χ² 194 / p 2e-44 | 5.7 EB05 4.4 · IC025 +2.0 3/3 methods agree | Reporting / coding artifact | serious PRR 3.7 · 72% consumer | no trial data cached |
| Bedridden | 11 | 5.3 3.0–9.6ROR 5.3 · χ² 35 / p 2e-9 | 4.4 EB05 2.7 · IC025 +1.1 3/3 methods agree | Not in label — unassessed | serious PRR 4.5 | no trial data cached |
| Neuralgia | 20 | 5.2 3.4–8.1ROR 5.3 · χ² 65 / p 5e-16 | 4.7 EB05 3.2 · IC025 +1.5 3/3 methods agree | Not in label — unassessed | serious PRR 6.3 | no trial data cached |
| Balance disorder | 69 | 5.1 4.0–6.4ROR 5.2 · χ² 222 / p 1e-50 | 4.9 EB05 4.0 · IC025 +1.9 3/3 methods agree | Labeled (related wording) related wording | serious PRR 3.6 | no trial data cached |
| Gastrointestinal disorder | 68 | 4.9 3.9–6.2ROR 5.0 · χ² 208 / p 2e-47 | 4.7 EB05 3.9 · IC025 +1.8 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 4.7 | no trial data cached |
| Generalised tonic-clonic seizure | 12 | 4.7 2.7–8.2ROR 4.7 · χ² 31 / p 1e-8 | 4.0 EB05 2.5 · IC025 +1.0 3/3 methods agree | Not in label — unassessed | serious PRR 4.5 | no trial data cached |
| Diplopia (double vision) | 19 | 4.7 3.0–7.3ROR 4.7 · χ² 51 / p 5e-13 | 4.2 EB05 2.9 · IC025 +1.3 3/3 methods agree | Not in label — unassessed | serious PRR 3.2 | no trial data cached |
| Oral herpes | 14 | 4.6 2.7–7.7ROR 4.6 · χ² 36 / p 1e-9 | 4.0 EB05 2.6 · IC025 +1.1 3/3 methods agree | Not in label — unassessed | serious PRR 9.5 | no trial data cached |
| Lower limb fracture | 13 | 4.3 2.5–7.5ROR 4.3 · χ² 30 / p 2e-8 | 3.8 EB05 2.4 · IC025 +1.0 3/3 methods agree | Not in label — unassessed | serious PRR 3.5 | no trial data cached |
| Irritable bowel syndrome | 14 | 4.2 2.5–7.0ROR 4.2 · χ² 31 / p 2e-8 | 3.7 EB05 2.4 · IC025 +1.0 3/3 methods agree | Not in label — unassessed | serious PRR 4.7 | no trial data cached |
| Upper limb fracture | 13 | 4.1 2.4–7.1ROR 4.1 · χ² 28 / p 7e-8 | 3.7 EB05 2.3 · IC025 +1.0 3/3 methods agree | Not in label — unassessed | serious PRR 3.8 | no trial data cached |
| Ankle fracture | 10 | 4.1 2.2–7.6ROR 4.1 · χ² 20 / p 3e-6 | 3.5 EB05 2.1 · IC025 +0.8 3/3 methods agree | Not in label — unassessed | serious PRR 2.2 | no trial data cached |
| Basal cell carcinoma | 10 | 4.1 2.2–7.6ROR 4.1 · χ² 20 / p 3e-6 | 3.5 EB05 2.1 · IC025 +0.8 3/3 methods agree | Not in label — unassessed | serious PRR 4.0 | no trial data cached |
| Fall | 212 | 4.1 3.6–4.6ROR 4.3 · χ² 493 / p 1e-109 | 4.0 EB05 3.6 · IC025 +1.8 3/3 methods agree | Not in label — unassessed | serious PRR 3.2 | no trial data cached |
| Gait disturbance | 118 | 3.9 3.3–4.7ROR 4.0 · χ² 255 / p 1e-57 | 3.9 EB05 3.3 · IC025 +1.6 3/3 methods agree | Not in label — unassessed | serious PRR 3.0 | no trial data cached |
| Leukocytosis | 11 | 3.9 2.1–7.0ROR 3.9 · χ² 21 / p 3e-6 | 3.4 EB05 2.1 · IC025 +0.8 3/3 methods agree | Not in label — unassessed | serious PRR 3.4 | no trial data cached |
| Leukopenia (low white blood cells) | 30 | 3.8 2.7–5.5ROR 3.9 · χ² 60 / p 5e-15 | 3.6 EB05 2.7 · IC025 +1.3 3/3 methods agree | Not in label — unassessed | serious PRR 3.7 · 97% clinician | no trial data cached |
| Cystitis | 19 | 3.8 2.4–5.9ROR 3.8 · χ² 36 / p 9e-10 | 3.5 EB05 2.4 · IC025 +1.0 3/3 methods agree | Not in label — unassessed | serious PRR 4.1 | no trial data cached |
| Rib fracture | 12 | 3.7 2.1–6.5ROR 3.7 · χ² 21 / p 2e-6 | 3.3 EB05 2.1 · IC025 +0.8 3/3 methods agree | Not in label — unassessed | serious PRR 3.9 | no trial data cached |
| Hot flush (hot flashes) | 44 | 3.7 2.8–5.0ROR 3.8 · χ² 85 / p 2e-20 | 3.6 EB05 2.8 · IC025 +1.3 3/3 methods agree | Labeled (related wording) related wording | serious PRR 3.1 · 77% consumer | no trial data cached |
| Covid-19 | 100 | 3.6 3.0–4.4ROR 3.7 · χ² 186 / p 1e-42 | 3.5 EB05 3.0 · IC025 +1.5 3/3 methods agree | Not in label — unassessed | serious PRR 4.1 | no trial data cached |
| Movement disorder | 18 | 3.6 2.2–5.6ROR 3.6 · χ² 31 / p 2e-8 | 3.3 EB05 2.2 · IC025 +0.9 3/3 methods agree | Not in label — unassessed | serious PRR 3.4 | no trial data cached |
| Burning sensation | 39 | 3.5 2.6–4.8ROR 3.6 · χ² 69 / p 6e-17 | 3.4 EB05 2.6 · IC025 +1.2 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 4.2 | no trial data cached |
| Urinary tract infection (bladder infection) | 87 | 3.3 2.6–4.0ROR 3.3 · χ² 135 / p 2e-31 | 3.2 EB05 2.7 · IC025 +1.3 3/3 methods agree | Not in label — unassessed | serious PRR 2.6 | no trial data cached |
| Disease recurrence | 24 | 3.2 2.1–4.8ROR 3.2 · χ² 34 / p 2e-9 | 3.0 EB05 2.2 · IC025 +0.9 3/3 methods agree | Reporting / coding artifact | serious PRR 3.3 | no trial data cached |
Trial evidence (ClinicalTrials.gov)
Trial cross-check not yet run for this drug (ClinicalTrials.gov pull covers the 800 most-reported drugs first).
Most frequently reported reactions
By raw co-report count, regardless of disproportionality. Common terms here are often the illness itself or generic outcomes.
| Reaction | Reports | PRR 95% CI · ROR · χ²/p | EBGM EB05 · IC025 | Label screen | Serious-only & strata | Trial cross-check |
|---|---|---|---|---|---|---|
| Flushing | 326 | 20.4 18.4–22.6ROR 22.5 · χ² 5,996 / p <1e-300 | 20.3 EB05 18.5 · IC025 +4.1 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 18.8 | no trial data cached |
| Multiple sclerosis relapse | 217 | 20.0 17.6–22.8ROR 21.4 · χ² 3,905 / p <1e-300 | 19.9 EB05 17.8 · IC025 +4.0 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious PRR 23.2 | no trial data cached |
| Fall | 212 | 4.1 3.6–4.6ROR 4.3 · χ² 493 / p 1e-109 | 4.0 EB05 3.6 · IC025 +1.8 3/3 methods agree | Not in label — unassessed | serious PRR 3.2 | no trial data cached |
| Multiple sclerosis | 151 | 20.0 17.1–23.4ROR 21.0 · χ² 2,711 / p <1e-300 | 19.9 EB05 17.4 · IC025 +4.0 3/3 methods agree | Likely indication confounding term in indications | serious PRR 23.2 | no trial data cached |
| Gait disturbance | 118 | 3.9 3.3–4.7ROR 4.0 · χ² 255 / p 1e-57 | 3.9 EB05 3.3 · IC025 +1.6 3/3 methods agree | Not in label — unassessed | serious PRR 3.0 | no trial data cached |
| Therapy interrupted | 114 | 10.5 8.8–12.6ROR 10.9 · χ² 975 / p 2e-214 | 10.4 EB05 8.8 · IC025 +3.0 3/3 methods agree | Reporting / coding artifact | serious PRR 16.3 | no trial data cached |
| Covid-19 | 100 | 3.6 3.0–4.4ROR 3.7 · χ² 186 / p 1e-42 | 3.5 EB05 3.0 · IC025 +1.5 3/3 methods agree | Not in label — unassessed | serious PRR 4.1 | no trial data cached |
| Abdominal pain upper | 99 | 3.1 2.5–3.7ROR 3.1 · χ² 137 / p 6e-32 | 3.0 EB05 2.6 · IC025 +1.3 3/3 methods agree | Labeled (related wording) related wording | serious PRR 3.3 | no trial data cached |
| Urinary tract infection (bladder infection) | 87 | 3.3 2.6–4.0ROR 3.3 · χ² 135 / p 2e-31 | 3.2 EB05 2.7 · IC025 +1.3 3/3 methods agree | Not in label — unassessed | serious PRR 2.6 | no trial data cached |
| Product substitution issue | 87 | 9.6 7.8–11.9ROR 9.9 · χ² 665 / p 6e-147 | 9.4 EB05 7.8 · IC025 +2.8 3/3 methods agree | Reporting / coding artifact | serious PRR 10.5 | no trial data cached |
| Lymphopenia | 80 | 36.4 29.3–45.2ROR 37.3 · χ² 2,703 / p <1e-300 | 35.9 EB05 29.8 · IC025 +4.5 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 34.4 · 97% clinician | no trial data cached |
| Paraesthesia (tingling/numbness) | 72 | 2.9 2.3–3.7ROR 2.9 · χ² 89 / p 2e-21 | 2.9 EB05 2.4 · IC025 +1.1 3/3 methods agree | Not in label — unassessed | serious PRR 2.7 | no trial data cached |
| Balance disorder | 69 | 5.1 4.0–6.4ROR 5.2 · χ² 222 / p 1e-50 | 4.9 EB05 4.0 · IC025 +1.9 3/3 methods agree | Labeled (related wording) related wording | serious PRR 3.6 | no trial data cached |
| Gastrointestinal disorder | 68 | 4.9 3.9–6.2ROR 5.0 · χ² 208 / p 2e-47 | 4.7 EB05 3.9 · IC025 +1.8 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 4.7 | no trial data cached |
| Therapy cessation | 48 | 6.0 4.5–7.9ROR 6.1 · χ² 194 / p 2e-44 | 5.7 EB05 4.4 · IC025 +2.0 3/3 methods agree | Reporting / coding artifact | serious PRR 3.7 · 72% consumer | no trial data cached |
Unlabeled candidate signals
These flagged terms were not found in the FDA label text and do not match an artifact pattern. They are the pairs that would merit a structured assessment (temporality, dose-response, biological plausibility, consistency across databases, trial or cohort evidence). The screen has not done that; string-matching misses label wording, and a strong PRR can still be stimulated reporting, co-medication, or the disease itself.
- Central nervous system lesion — n=37, PRR 17.1
- Muscle spasticity — n=27, PRR 13.9
- Rebound effect — n=23, PRR 12.9
- Neuralgia — n=20, PRR 5.2
- Fall — n=212, PRR 4.1
- Gait disturbance — n=118, PRR 3.9
- Leukopenia — n=30, PRR 3.8
- Covid-19 — n=100, PRR 3.6
- Urinary tract infection — n=87, PRR 3.3
✓ A hand-written Bradford Hill causality assessment exists for this drug: Tenofovir disoproxil fumarate ↔ Bone loss.
Want to assess one of these properly? The runbook describes the Bradford Hill / trial-evidence workflow used on the assessment page, and handoff_top1000_signals.csv lists the strongest unassessed pairs across all drugs.
Common questions
What are the most reported side effects of Dimethyl?
In FDA FAERS, the most frequently co-reported reaction terms for Dimethyl are flushing, multiple sclerosis relapse, fall, multiple sclerosis, gait disturbance, covid-19. These are report counts, not rates: FAERS has no denominator, reporting is voluntary and uneven, and a term can be reported because of the illness being treated rather than the drug.
Does Dimethyl have an FDA boxed warning?
No. The FDA label retrieved for Dimethyl has no boxed warning; see the label's Warnings and Precautions for the recognised risks.
Do FAERS signals prove that Dimethyl causes these side effects?
No. A disproportionality signal (PRR, ROR) means a reaction is reported more often with this drug than with others in the database. That can reflect a real effect, but also the disease being treated, stimulated reporting after news or litigation, co-medications, or how reports are coded. Causality needs temporality, dose-response, biological plausibility, consistency across data sources and, ideally, trial or cohort evidence. This page screens each term against the FDA label and ClinicalTrials.gov results; it does not establish causation.
Sources & methods
- FDA label via openFDA (set ID c3f65da9-f5f4-4161-aded-c23b16fd49ed, effective 20240423; matched on
openfda.generic_name.exact:"DIMETHYL FUMARATE KIT") - Bayesian shrinkage measures computed offline over all 1,317,300 cached pairs: BCPNN information component (IC, with Norén closed-form IC025) and MGPS empirical-Bayes geometric mean (EBGM, EB05) with a two-component gamma prior fitted by maximum marginal likelihood (α₁=0.57, β₁=0.02, α₂=1.42, β₂=0.70, w=0.17); unstratified
- FAERS pair statistics from the OpenPV build of 2026-09-14 (openFDA
count=aggregation, fieldpatient.drug.openfda.generic_name.exact, 106 reaction terms, min 3 co-reports); PRR/ROR with 95% CI, chi-square with Yates correction - Serious-only and stratified counts (serious:1, patient.patientsex, primarysource.qualification) from openFDA count queries; serious-only PRR uses the drug serious report total and the term global serious total (N_serious=11,882,979); strata shown only when n ≥ 20
- Seriousness and sex counts from openFDA
count=serious,patient.patientsex,seriousnessdeath
Page generated 2026-10-08. Label and PubChem text are retrieved automatically and may lag the current label; always check the current prescribing information. OpenPV is a beta research tool of the Open Source Medicine Foundation.