Menthol and Unspecified Form side effects: what 605 FDA adverse event reports show
Drug class
Not stated in label
Label matched
Menthol (Biofreeze)
Who reports
605 reports · 60% serious · 36 with death outcome · 79% female
Used for
Temporary relief from minor aches and pains of sore muscles and joints associated with: arthritis backache strains and sprains
Boxed warning
None in the current label
Causality screen of the 5 strongest signals
What the badges mean
- 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.
- 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. 6 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 |
|---|---|---|---|---|---|---|
| Seasonal allergy | 9 | 22.0 11.5–42.1ROR 22.3 · χ² 160 / p 6e-37 | 20.6 EB05 10.7 · IC025 +2.2 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=6 | no trial data cached |
| Application site erythema | 12 | 15.7 9.0–27.6ROR 16.0 · χ² 151 / p 5e-35 | 14.6 EB05 7.9 · IC025 +2.3 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=11 | no trial data cached |
| Application site pain | 8 | 12.5 6.3–25.0ROR 12.7 · χ² 74 / p 4e-18 | 9.9 EB05 4.6 · IC025 +1.7 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=7 | no trial data cached |
| Device dislocation | 5 | 4.0 1.7–9.5ROR 4.0 · χ² 8 / p 0.002 | 3.1 EB05 1.5 · IC025 +0.1 | Reporting / coding artifact | serious PRR 2.0 | no trial data cached |
| Device issue | 9 | 3.6 1.9–6.8ROR 3.6 · χ² 14 / p 8e-5 | 3.1 EB05 1.8 · IC025 +0.5 | Reporting / coding artifact | serious PRR 12.6 | 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 |
|---|---|---|---|---|---|---|
| Application site erythema | 12 | 15.7 9.0–27.6ROR 16.0 · χ² 151 / p 5e-35 | 14.6 EB05 7.9 · IC025 +2.3 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=11 | no trial data cached |
| Device issue | 9 | 3.6 1.9–6.8ROR 3.6 · χ² 14 / p 8e-5 | 3.1 EB05 1.8 · IC025 +0.5 | Reporting / coding artifact | serious PRR 12.6 | no trial data cached |
| Seasonal allergy | 9 | 22.0 11.5–42.1ROR 22.3 · χ² 160 / p 6e-37 | 20.6 EB05 10.7 · IC025 +2.2 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=6 | no trial data cached |
| Application site pain | 8 | 12.5 6.3–25.0ROR 12.7 · χ² 74 / p 4e-18 | 9.9 EB05 4.6 · IC025 +1.7 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=7 | no trial data cached |
| Device dislocation | 5 | 4.0 1.7–9.5ROR 4.0 · χ² 8 / p 0.002 | 3.1 EB05 1.5 · IC025 +0.1 | Reporting / coding artifact | serious PRR 2.0 | no trial data cached |
| Coronary artery occlusion | 4 | 10.0 3.8–26.6ROR 10.1 · χ² 24 / p 5e-7 | 5.8 EB05 2.3 · IC025 +0.6 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 9.7 | no trial data cached |
| Application site irritation | 4 | 11.1 4.2–29.5ROR 11.2 · χ² 27 / p 9e-8 | 6.4 EB05 2.4 · IC025 +0.6 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=4 | no trial data cached |
| Device breakage | 3 | 2.6 0.9–8.1ROR 2.6 · χ² 2 / p 0.101 | 2.2 EB05 0.9 · IC025 -1.0 PRR-only: not supported by EBGM or IC | Reporting / coding artifact | serious PRR 3.5 | no trial data cached |
| Product adhesion issue | 3 | 2.9 0.9–9.0ROR 2.9 · χ² 2 / p 0.073 | 2.3 EB05 0.9 · IC025 -0.9 PRR-only: not supported by EBGM or IC | Reporting / coding artifact | – | no trial data cached |
| Application site pruritus | 3 | 4.6 1.5–14.1ROR 4.6 · χ² 5 / p 0.012 | 3.0 EB05 1.2 · IC025 -0.5 PRR-only: not supported by EBGM or IC | No label text to screen label has no adverse-reaction text | serious n=3 | no trial data cached |
| Inability to afford medication | 3 | 10.5 3.4–32.5ROR 10.6 · χ² 17 / p 2e-5 | 5.3 EB05 1.8 · IC025 +0.1 | No label text to screen label has no adverse-reaction text | serious n=2 | 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 Menthol and Unspecified Form?
In FDA FAERS, the most frequently co-reported reaction terms for Menthol and Unspecified Form are application site erythema, seasonal allergy, application site pain, coronary artery occlusion, application site irritation, application site pruritus. 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 Menthol and Unspecified Form have an FDA boxed warning?
No. The FDA label retrieved for Menthol and Unspecified Form has no boxed warning; see the label's Warnings and Precautions for the recognised risks.
Do FAERS signals prove that Menthol and Unspecified Form 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 00bb462a-27d0-6f74-e063-6394a90a90ec, effective 20260513; matched on
openfda.generic_name.exact:"MENTHOL") - 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, 11 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.