Simethicone side effects: what 4,666 FDA adverse event reports show
Drug class
Not stated in label
Brand names
Gas Relief
Who reports
4,666 reports · 63% serious · 367 with death outcome · 66% female
Used for
relieves bloating, pressure, or fullness commonly referred to as gas
Boxed warning
None in the current label
Causality screen of the 40 strongest signals
What the badges mean
- 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.
- No label text to screen No validated FDA label was retrievable for this product, so the screen could not run. Disproportionality only.
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. 471 further terms are in the interactive explorer. Reaction links open the term's cross-drug page.
| Reaction | Reports | PRR 95% CI · ROR · χ²/p | EBGM EB05 · IC025 | Label screen | Serious-only & strata | Trial cross-check |
|---|---|---|---|---|---|---|
| Flatulence (gas) | 267 | 21.3 18.9–23.9ROR 22.5 · χ² 5,123 / p <1e-300 | 21.1 EB05 19.1 · IC025 +4.1 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 18.7 · 73% consumer | no trial data cached |
| Eructation (belching) | 52 | 12.3 9.4–16.1ROR 12.4 · χ² 527 / p 6e-117 | 12.0 EB05 9.4 · IC025 +3.0 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=29 · 80% consumer | no trial data cached |
| Malnutrition | 24 | 9.7 6.5–14.5ROR 9.8 · χ² 179 / p 5e-41 | 8.8 EB05 6.0 · IC025 +2.4 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 9.1 | no trial data cached |
| Abdominal distension (bloating) | 224 | 9.7 8.5–11.0ROR 10.1 · χ² 1,740 / p <1e-300 | 9.6 EB05 8.6 · IC025 +3.0 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 9.1 | no trial data cached |
| Gastrointestinal pain | 22 | 9.0 5.9–13.7ROR 9.1 · χ² 149 / p 2e-34 | 8.1 EB05 5.4 · IC025 +2.2 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 7.9 | no trial data cached |
| Atelectasis | 19 | 8.8 5.6–13.8ROR 8.8 · χ² 124 / p 5e-29 | 7.7 EB05 5.0 · IC025 +2.1 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 8.1 | no trial data cached |
| Impaired gastric emptying | 24 | 8.5 5.7–12.6ROR 8.5 · χ² 150 / p 8e-35 | 7.6 EB05 5.2 · IC025 +2.2 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 8.3 | no trial data cached |
| Small intestinal obstruction | 22 | 8.1 5.3–12.2ROR 8.1 · χ² 129 / p 4e-30 | 7.1 EB05 4.9 · IC025 +2.1 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 7.4 | no trial data cached |
| Coeliac disease | 17 | 7.8 4.8–12.5ROR 7.8 · χ² 94 / p 2e-22 | 6.7 EB05 4.3 · IC025 +1.9 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 8.8 | no trial data cached |
| Irritable bowel syndrome | 37 | 7.8 5.6–10.7ROR 7.8 · χ² 212 / p 3e-48 | 7.2 EB05 5.4 · IC025 +2.3 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 6.5 | no trial data cached |
| Hiatus hernia | 22 | 7.6 5.0–11.6ROR 7.6 · χ² 120 / p 4e-28 | 6.7 EB05 4.6 · IC025 +2.0 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 6.8 · ♀ 91% (drug 66%) · 80% consumer | no trial data cached |
| Sleep apnoea syndrome | 31 | 7.3 5.1–10.3ROR 7.3 · χ² 162 / p 3e-37 | 6.7 EB05 4.9 · IC025 +2.1 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 6.1 | no trial data cached |
| Gallbladder disorder | 28 | 7.0 4.9–10.2ROR 7.1 · χ² 139 / p 3e-32 | 6.4 EB05 4.6 · IC025 +2.0 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 7.0 · ♀ 89% (drug 66%) · 76% consumer | no trial data cached |
| Seasonal allergy | 22 | 7.0 4.6–10.6ROR 7.0 · χ² 107 / p 2e-25 | 6.2 EB05 4.3 · IC025 +1.9 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=10 · ♀ 100% (drug 66%) · 82% consumer | no trial data cached |
| Flank pain | 14 | 6.7 4.0–11.3ROR 6.7 · χ² 62 / p 1e-15 | 5.6 EB05 3.5 · IC025 +1.6 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 8.0 | no trial data cached |
| Gastritis | 38 | 6.5 4.7–8.9ROR 6.5 · χ² 171 / p 2e-39 | 6.1 EB05 4.6 · IC025 +2.1 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 6.0 | no trial data cached |
| Mitral valve incompetence | 16 | 6.3 3.9–10.4ROR 6.4 · χ² 67 / p 2e-16 | 5.5 EB05 3.5 · IC025 +1.6 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 5.8 | no trial data cached |
| Intervertebral disc degeneration | 13 | 6.3 3.6–10.8ROR 6.3 · χ² 52 / p 2e-13 | 5.2 EB05 3.2 · IC025 +1.5 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 6.5 | no trial data cached |
| Cholelithiasis | 45 | 6.2 4.6–8.2ROR 6.2 · χ² 189 / p 2e-43 | 5.8 EB05 4.5 · IC025 +2.0 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 5.9 | no trial data cached |
| Blood iron decreased | 16 | 6.1 3.7–9.9ROR 6.1 · χ² 63 / p 1e-15 | 5.3 EB05 3.4 · IC025 +1.6 3/3 methods agree | Lab value / disease marker | serious PRR 5.7 | no trial data cached |
| Frequent bowel movements | 36 | 6.0 4.3–8.3ROR 6.0 · χ² 145 / p 9e-34 | 5.6 EB05 4.2 · IC025 +1.9 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 4.0 · 79% consumer | no trial data cached |
| Oral pain | 30 | 6.0 4.2–8.6ROR 6.0 · χ² 120 / p 3e-28 | 5.5 EB05 4.0 · IC025 +1.9 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 7.3 | no trial data cached |
| Ileus | 16 | 5.8 3.6–9.5ROR 5.9 · χ² 59 / p 7e-15 | 5.1 EB05 3.3 · IC025 +1.5 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 5.3 | no trial data cached |
| Cardiomegaly | 16 | 5.8 3.5–9.4ROR 5.8 · χ² 59 / p 9e-15 | 5.0 EB05 3.3 · IC025 +1.5 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 5.1 | no trial data cached |
| Bacteraemia | 15 | 5.7 3.5–9.5ROR 5.7 · χ² 54 / p 1e-13 | 4.9 EB05 3.2 · IC025 +1.4 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 5.2 | no trial data cached |
| Cholecystitis | 15 | 5.7 3.4–9.4ROR 5.7 · χ² 53 / p 2e-13 | 4.9 EB05 3.1 · IC025 +1.4 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 5.2 | no trial data cached |
| Faeces discoloured | 27 | 5.6 3.8–8.1ROR 5.6 · χ² 97 / p 3e-23 | 5.1 EB05 3.7 · IC025 +1.7 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 4.8 | no trial data cached |
| Clostridium difficile colitis | 13 | 5.5 3.2–9.5ROR 5.5 · χ² 43 / p 2e-11 | 4.7 EB05 2.9 · IC025 +1.3 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 5.1 | no trial data cached |
| Renal tubular necrosis | 12 | 5.5 3.1–9.6ROR 5.5 · χ² 40 / p 2e-10 | 4.6 EB05 2.8 · IC025 +1.2 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 5.0 | no trial data cached |
| Hospice care | 12 | 5.5 3.1–9.6ROR 5.5 · χ² 39 / p 2e-10 | 4.6 EB05 2.8 · IC025 +1.2 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 5.4 | no trial data cached |
| Constipation | 263 | 5.5 4.9–6.1ROR 5.7 · χ² 962 / p 2e-211 | 5.4 EB05 4.9 · IC025 +2.2 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 5.9 | no trial data cached |
| Haematocrit decreased | 24 | 5.4 3.6–8.0ROR 5.4 · χ² 82 / p 8e-20 | 4.9 EB05 3.5 · IC025 +1.6 3/3 methods agree | Lab value / disease marker | serious PRR 4.8 | no trial data cached |
| Hypophagia | 30 | 5.3 3.7–7.6ROR 5.3 · χ² 101 / p 5e-24 | 4.9 EB05 3.6 · IC025 +1.7 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 5.1 | no trial data cached |
| Dyspepsia (indigestion) | 112 | 5.1 4.3–6.2ROR 5.2 · χ² 369 / p 1e-82 | 5.0 EB05 4.3 · IC025 +2.0 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 5.6 · 82% consumer | no trial data cached |
| Candida infection (yeast infection) | 19 | 5.1 3.3–8.0ROR 5.1 · χ² 59 / p 9e-15 | 4.6 EB05 3.1 · IC025 +1.4 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 4.9 | no trial data cached |
| Gastrooesophageal reflux disease (acid reflux) | 91 | 5.1 4.2–6.2ROR 5.2 · χ² 296 / p 1e-66 | 5.0 EB05 4.2 · IC025 +2.0 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 4.5 · 71% consumer | no trial data cached |
| Haemorrhoids | 22 | 5.1 3.3–7.7ROR 5.1 · χ² 68 / p 1e-16 | 4.6 EB05 3.2 · IC025 +1.5 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 5.2 | no trial data cached |
| Sinus disorder | 22 | 5.0 3.3–7.6ROR 5.0 · χ² 66 / p 2e-16 | 4.5 EB05 3.2 · IC025 +1.5 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 5.3 · ♀ 91% (drug 66%) | no trial data cached |
| Increased tendency to bruise | 10 | 4.9 2.6–9.0ROR 4.9 · χ² 27 / p 1e-7 | 4.1 EB05 2.4 · IC025 +1.0 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=5 | no trial data cached |
| Nocturia (night-time urination) | 13 | 4.8 2.8–8.3ROR 4.8 · χ² 36 / p 1e-9 | 4.2 EB05 2.6 · IC025 +1.1 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 5.2 | no trial data cached |
Trial evidence (ClinicalTrials.gov)
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 |
|---|---|---|---|---|---|---|
| Nausea | 494 | 2.8 2.6–3.1ROR 3.0 · χ² 596 / p 6e-132 | 2.8 EB05 2.6 · IC025 +1.3 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 3.2 | no trial data cached |
| Diarrhoea (diarrhea) | 461 | 3.2 2.9–3.5ROR 3.5 · χ² 724 / p 1e-159 | 3.2 EB05 3.0 · IC025 +1.5 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 3.1 | no trial data cached |
| Fatigue (tiredness) | 451 | 2.6 2.4–2.8ROR 2.8 · χ² 461 / p 1e-102 | 2.6 EB05 2.4 · IC025 +1.2 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 2.9 | no trial data cached |
| Pain | 274 | 2.0 1.8–2.2ROR 2.1 · χ² 140 / p 2e-32 | 2.0 EB05 1.8 · IC025 +0.8 | No label text to screen label has no adverse-reaction text | serious PRR 2.1 | no trial data cached |
| Flatulence (gas) | 267 | 21.3 18.9–23.9ROR 22.5 · χ² 5,123 / p <1e-300 | 21.1 EB05 19.1 · IC025 +4.1 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 18.7 · 73% consumer | no trial data cached |
| Vomiting | 266 | 2.5 2.3–2.9ROR 2.6 · χ² 254 / p 2e-57 | 2.5 EB05 2.3 · IC025 +1.1 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 2.6 | no trial data cached |
| Constipation | 263 | 5.5 4.9–6.1ROR 5.7 · χ² 962 / p 2e-211 | 5.4 EB05 4.9 · IC025 +2.2 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 5.9 | no trial data cached |
| Abdominal distension (bloating) | 224 | 9.7 8.5–11.0ROR 10.1 · χ² 1,740 / p <1e-300 | 9.6 EB05 8.6 · IC025 +3.0 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 9.1 | no trial data cached |
| Asthenia (weakness) | 215 | 2.6 2.3–2.9ROR 2.6 · χ² 207 / p 3e-47 | 2.6 EB05 2.3 · IC025 +1.1 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 2.5 | no trial data cached |
| Abdominal pain | 199 | 3.8 3.4–4.4ROR 4.0 · χ² 420 / p 1e-93 | 3.8 EB05 3.4 · IC025 +1.7 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 3.5 | no trial data cached |
| Abdominal pain upper | 198 | 4.3 3.8–5.0ROR 4.5 · χ² 508 / p 1e-112 | 4.3 EB05 3.8 · IC025 +1.9 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 4.7 · 79% consumer | no trial data cached |
| Weight decreased (weight loss) | 196 | 3.2 2.7–3.6ROR 3.2 · χ² 290 / p 3e-65 | 3.1 EB05 2.8 · IC025 +1.4 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 3.1 | no trial data cached |
| Fall | 169 | 2.3 2.0–2.6ROR 2.3 · χ² 122 / p 1e-28 | 2.3 EB05 2.0 · IC025 +0.9 | No label text to screen label has no adverse-reaction text | serious PRR 2.2 | no trial data cached |
| Decreased appetite (loss of appetite) | 163 | 3.2 2.7–3.7ROR 3.2 · χ² 241 / p 1e-54 | 3.1 EB05 2.8 · IC025 +1.4 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 2.9 | no trial data cached |
| Arthralgia (joint pain) | 162 | 1.8 1.5–2.0ROR 1.8 · χ² 53 / p 2e-13 | 1.8 EB05 1.5 · IC025 +0.5 | No label text to screen label has no adverse-reaction text | serious PRR 1.9 · 72% consumer | no trial data cached |
Unlabeled candidate signals
Every screened signal with n ≥ 20 was either labeled, an indication term, or an artifact pattern — no unlabeled candidate stood out in the top signals.
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 Simethicone?
In FDA FAERS, the most frequently co-reported reaction terms for Simethicone are nausea, diarrhoea, fatigue, pain, flatulence, vomiting. 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 Simethicone have an FDA boxed warning?
No. The FDA label retrieved for Simethicone has no boxed warning; see the label's Warnings and Precautions for the recognised risks.
Do FAERS signals prove that Simethicone 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 011859d8-3d0f-4ca7-a98b-4150054154dc, effective 20260901; matched on
openfda.generic_name.exact:"SIMETHICONE") - 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, 511 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.