Menthol side effects: what 3,296 FDA adverse event reports show
Drug class
Not stated in label
Brand names
Biofreeze
Who reports
3,296 reports · 60% serious · 213 with death outcome · 68% 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 40 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.
- 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. 159 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 |
|---|---|---|---|---|---|---|
| Application site pain | 118 | 34.2 28.6–40.9ROR 35.4 · χ² 3,754 / p <1e-300 | 33.9 EB05 29.0 · IC025 +4.6 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=64 · 97% consumer | no trial data cached |
| Hypercholesterolaemia | 36 | 24.0 17.3–33.2ROR 24.2 · χ² 767 / p 4e-169 | 23.6 EB05 17.8 · IC025 +3.6 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 24.3 · ♀ 100% (drug 68%) · 100% clinician | no trial data cached |
| Application site erythema | 74 | 17.9 14.3–22.4ROR 18.3 · χ² 1,162 / p 6e-255 | 17.8 EB05 14.6 · IC025 +3.6 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=45 · 95% consumer | no trial data cached |
| Joint dislocation | 27 | 16.3 11.2–23.8ROR 16.4 · χ² 372 / p 3e-83 | 16.0 EB05 11.3 · IC025 +3.0 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 16.9 | no trial data cached |
| Scar | 41 | 15.2 11.2–20.6ROR 15.4 · χ² 529 / p 2e-117 | 15.0 EB05 11.4 · IC025 +3.2 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 19.0 · 95% consumer | no trial data cached |
| Secretion discharge | 29 | 14.9 10.4–21.5ROR 15.1 · χ² 363 / p 4e-81 | 14.6 EB05 10.4 · IC025 +3.0 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 21.8 · ♀ 93% (drug 68%) | no trial data cached |
| Scratch | 22 | 13.5 8.9–20.5ROR 13.6 · χ² 242 / p 7e-55 | 12.9 EB05 8.5 · IC025 +2.7 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=21 · ♀ 100% (drug 68%) | no trial data cached |
| Dizziness postural | 20 | 13.2 8.6–20.5ROR 13.3 · χ² 214 / p 9e-49 | 12.5 EB05 8.1 · IC025 +2.6 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=20 · ♀ 100% (drug 68%) | no trial data cached |
| Helicobacter infection | 21 | 13.1 8.5–20.1ROR 13.2 · χ² 222 / p 1e-50 | 12.4 EB05 8.1 · IC025 +2.6 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 13.2 · ♀ 100% (drug 68%) · 100% clinician | no trial data cached |
| Blister | 97 | 11.0 9.0–13.4ROR 11.3 · χ² 873 / p 3e-192 | 10.8 EB05 9.1 · IC025 +3.0 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 15.8 · 88% consumer | no trial data cached |
| Autoimmune disorder | 16 | 10.6 6.5–17.3ROR 10.7 · χ² 130 / p 2e-30 | 9.3 EB05 5.7 · IC025 +2.2 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 10.9 | no trial data cached |
| Scab | 18 | 10.1 6.4–16.0ROR 10.1 · χ² 138 / p 3e-32 | 8.9 EB05 5.7 · IC025 +2.2 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=16 | no trial data cached |
| Hip arthroplasty | 24 | 10.0 6.7–15.0ROR 10.1 · χ² 186 / p 1e-42 | 9.2 EB05 6.2 · IC025 +2.4 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 9.5 | no trial data cached |
| Infusion site pain | 19 | 9.5 6.0–14.8ROR 9.5 · χ² 135 / p 1e-31 | 8.3 EB05 5.4 · IC025 +2.2 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=9 | no trial data cached |
| Joint range of motion decreased | 19 | 9.0 5.8–14.2ROR 9.1 · χ² 128 / p 6e-30 | 7.9 EB05 5.2 · IC025 +2.1 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 11.0 | no trial data cached |
| Seasonal allergy | 20 | 9.0 5.8–13.9ROR 9.1 · χ² 134 / p 2e-31 | 8.0 EB05 5.3 · IC025 +2.2 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=12 · 85% consumer | no trial data cached |
| Irritable bowel syndrome | 29 | 8.6 6.0–12.4ROR 8.7 · χ² 188 / p 5e-43 | 7.9 EB05 5.7 · IC025 +2.3 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 10.1 · 100% clinician | no trial data cached |
| Sciatica | 21 | 8.4 5.5–12.9ROR 8.5 · χ² 130 / p 2e-30 | 7.4 EB05 5.0 · IC025 +2.1 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 9.8 | no trial data cached |
| Erythema multiforme | 12 | 8.2 4.6–14.4ROR 8.2 · χ² 69 / p 6e-17 | 6.6 EB05 3.9 · IC025 +1.7 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 8.1 | no trial data cached |
| Fibromyalgia | 29 | 7.6 5.3–10.9ROR 7.6 · χ² 159 / p 8e-37 | 6.9 EB05 5.0 · IC025 +2.1 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 7.9 · ♀ 100% (drug 68%) | no trial data cached |
| No adverse event | 209 | 7.5 6.6–8.5ROR 7.9 · χ² 1,177 / p 3e-258 | 7.4 EB05 6.6 · IC025 +2.7 3/3 methods agree | Reporting / coding artifact | serious PRR 1.7 · 94% consumer | no trial data cached |
| Nerve injury | 13 | 7.4 4.3–12.7ROR 7.4 · χ² 66 / p 3e-16 | 6.1 EB05 3.7 · IC025 +1.6 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 8.5 | no trial data cached |
| Burning sensation | 80 | 7.2 5.8–9.0ROR 7.4 · χ² 426 / p 7e-95 | 7.0 EB05 5.8 · IC025 +2.4 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 6.5 · 93% consumer | no trial data cached |
| Impaired healing | 36 | 7.0 5.0–9.6ROR 7.0 · χ² 178 / p 6e-41 | 6.5 EB05 4.9 · IC025 +2.1 3/3 methods agree | Reporting / coding artifact | serious PRR 7.8 · ♀ 100% (drug 68%) | no trial data cached |
| Prescribed overdose | 21 | 6.9 4.5–10.6ROR 6.9 · χ² 100 / p 8e-24 | 6.1 EB05 4.2 · IC025 +1.9 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 10.7 | no trial data cached |
| Folliculitis | 11 | 6.8 3.7–12.2ROR 6.8 · χ² 48 / p 2e-12 | 5.4 EB05 3.2 · IC025 +1.4 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 7.6 | no trial data cached |
| Joint stiffness | 27 | 6.5 4.5–9.5ROR 6.6 · χ² 121 / p 2e-28 | 5.9 EB05 4.3 · IC025 +1.9 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 10.5 · 92% clinician | no trial data cached |
| Skin burning sensation | 72 | 6.4 5.1–8.1ROR 6.6 · χ² 326 / p 4e-73 | 6.2 EB05 5.1 · IC025 +2.2 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 15.2 · 91% consumer | no trial data cached |
| Knee arthroplasty | 21 | 6.4 4.2–9.8ROR 6.4 · χ² 90 / p 1e-21 | 5.7 EB05 3.9 · IC025 +1.8 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 6.4 | no trial data cached |
| Lip swelling | 33 | 6.3 4.5–8.9ROR 6.4 · χ² 142 / p 4e-33 | 5.8 EB05 4.3 · IC025 +2.0 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 9.3 | no trial data cached |
| Bronchospasm (airway tightening) | 14 | 6.2 3.7–10.5ROR 6.2 · χ² 56 / p 3e-14 | 5.3 EB05 3.3 · IC025 +1.5 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 5.6 | no trial data cached |
| C-reactive protein increased | 34 | 5.9 4.3–8.3ROR 6.0 · χ² 135 / p 2e-31 | 5.5 EB05 4.1 · IC025 +1.9 3/3 methods agree | Lab value / disease marker | serious PRR 5.6 · ♀ 90% (drug 68%) · 97% clinician | no trial data cached |
| End stage renal disease | 17 | 5.9 3.6–9.4ROR 5.9 · χ² 64 / p 7e-16 | 5.1 EB05 3.4 · IC025 +1.5 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 5.6 | no trial data cached |
| Laryngitis | 10 | 5.9 3.2–10.9ROR 5.9 · χ² 36 / p 1e-9 | 4.7 EB05 2.8 · IC025 +1.2 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=10 | no trial data cached |
| Blood calcium decreased | 10 | 5.6 3.0–10.5ROR 5.6 · χ² 34 / p 3e-9 | 4.6 EB05 2.7 · IC025 +1.1 3/3 methods agree | Lab value / disease marker | serious PRR 6.7 | no trial data cached |
| Pemphigus | 11 | 5.6 3.1–10.1ROR 5.6 · χ² 37 / p 5e-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 |
| Dermatitis contact | 10 | 5.6 3.0–10.4ROR 5.6 · χ² 33 / p 4e-9 | 4.5 EB05 2.7 · IC025 +1.1 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=7 | no trial data cached |
| Insurance issue | 13 | 5.6 3.2–9.6ROR 5.6 · χ² 44 / 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 9.3 | no trial data cached |
| Hand deformity | 11 | 5.3 3.0–9.6ROR 5.4 · χ² 35 / p 2e-9 | 4.4 EB05 2.7 · IC025 +1.1 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 5.6 | no trial data cached |
| Bursitis | 10 | 5.3 2.8–9.8ROR 5.3 · χ² 30 / p 2e-8 | 4.3 EB05 2.5 · IC025 +1.1 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 5.3 | 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 |
|---|---|---|---|---|---|---|
| Pain | 274 | 2.8 2.5–3.2ROR 3.0 · χ² 332 / p 2e-74 | 2.8 EB05 2.5 · IC025 +1.3 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 2.9 | no trial data cached |
| No adverse event | 209 | 7.5 6.6–8.5ROR 7.9 · χ² 1,177 / p 3e-258 | 7.4 EB05 6.6 · IC025 +2.7 3/3 methods agree | Reporting / coding artifact | serious PRR 1.7 · 94% consumer | no trial data cached |
| Cough | 132 | 3.0 2.5–3.5ROR 3.1 · χ² 176 / p 2e-40 | 3.0 EB05 2.6 · IC025 +1.3 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 3.7 | no trial data cached |
| Back pain | 120 | 3.3 2.8–3.9ROR 3.4 · χ² 190 / p 2e-43 | 3.2 EB05 2.8 · IC025 +1.4 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 3.8 | no trial data cached |
| Erythema (skin redness) | 120 | 3.7 3.1–4.4ROR 3.8 · χ² 237 / p 8e-54 | 3.7 EB05 3.1 · IC025 +1.6 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 5.4 · 70% consumer | no trial data cached |
| Application site pain | 118 | 34.2 28.6–40.9ROR 35.4 · χ² 3,754 / p <1e-300 | 33.9 EB05 29.0 · IC025 +4.6 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=64 · 97% consumer | no trial data cached |
| Blister | 97 | 11.0 9.0–13.4ROR 11.3 · χ² 873 / p 3e-192 | 10.8 EB05 9.1 · IC025 +3.0 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 15.8 · 88% consumer | no trial data cached |
| Hypersensitivity (allergic reaction) | 87 | 3.0 2.4–3.7ROR 3.0 · χ² 113 / p 8e-27 | 2.9 EB05 2.5 · IC025 +1.2 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 4.5 | no trial data cached |
| Nasopharyngitis (common cold) | 82 | 2.8 2.3–3.5ROR 2.9 · χ² 95 / p 9e-23 | 2.8 EB05 2.3 · IC025 +1.1 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 4.6 | no trial data cached |
| Burning sensation | 80 | 7.2 5.8–9.0ROR 7.4 · χ² 426 / p 7e-95 | 7.0 EB05 5.8 · IC025 +2.4 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 6.5 · 93% consumer | no trial data cached |
| Urticaria (hives) | 78 | 3.0 2.4–3.7ROR 3.0 · χ² 101 / p 4e-24 | 2.9 EB05 2.4 · IC025 +1.2 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 4.7 | no trial data cached |
| Application site erythema | 74 | 17.9 14.3–22.4ROR 18.3 · χ² 1,162 / p 6e-255 | 17.8 EB05 14.6 · IC025 +3.6 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious n=45 · 95% consumer | no trial data cached |
| Sinusitis | 72 | 4.4 3.5–5.6ROR 4.5 · χ² 190 / p 2e-43 | 4.3 EB05 3.6 · IC025 +1.7 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 7.0 · ♀ 94% (drug 68%) | no trial data cached |
| Skin burning sensation | 72 | 6.4 5.1–8.1ROR 6.6 · χ² 326 / p 4e-73 | 6.2 EB05 5.1 · IC025 +2.2 3/3 methods agree | No label text to screen label has no adverse-reaction text | serious PRR 15.2 · 91% consumer | no trial data cached |
| Contusion | 57 | 3.8 2.9–4.9ROR 3.8 · χ² 113 / p 8e-27 | 3.7 EB05 2.9 · 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 |
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?
In FDA FAERS, the most frequently co-reported reaction terms for Menthol are pain, cough, back pain, erythema, application site pain, blister. 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 have an FDA boxed warning?
No. The FDA label retrieved for Menthol has no boxed warning; see the label's Warnings and Precautions for the recognised risks.
Do FAERS signals prove that Menthol 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, 199 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.