Camphor

Evidence Level: L5

Predicted Indications: 9

Camphor

Pharmacist Assessment Report

Camphor: From an Unspecified Topical Counter-Irritant to Migraine Disorder

One-Sentence Summary

Camphor is a topical counter-irritant, marketed in Australia as an ingredient of Goanna Heat Cream. No approved indication text is recorded in the data compiled for this report. The TxGNN model predicts it may be relevant to migraine disorder, but there are no registered clinical trials and only 3 low-tier publications (two case reports or series and one unrelated historical review), plus one preclinical animal study found under a related migraine entry. This is a research question, not a treatment recommendation.

Quick Overview

Item	Content
Original Indication	Not recorded (no approved indication text in the ARTG data)
Predicted New Indication	Migraine disorder
TxGNN Prediction Score	0.9985
Evidence Level	L5
Australia Market Status	Listed on the PBS Schedule (1 of 1 items) – TGA (ARTG) registration status is not included in this data
Number of PBS Items	1 (valid: 1)
Recommended Decision	Hold

Why is This Prediction Reasonable?

Detailed mechanism of action data is not available in the data compiled for this report. Based on general pharmacology, camphor is understood to act as a TRPM8 agonist and a TRPV1/TRPA1 modulator. Topical or inhaled counter-irritant effects could plausibly influence trigeminovascular pain signalling, which is relevant to migraine.

The original indication for the Australian product is not documented, so the relationship between the original and new indications cannot be assessed directly. Camphor is used as a topical rubefacient and counter-irritant for muscle and joint discomfort, and this is a different clinical setting from migraine.

The supporting literature is weak:

Two case reports or series describe cluster headache temporally linked to toothpastes containing camphor and eucalyptus oils. These describe a possible trigger, not a benefit, and cluster headache is a different condition from migraine.
A 2026 animal-model study (reserpine-induced migraine) reports that natural (+)-camphor reduced migraine-like changes via the p38β MAPK/ATF2 pathway. It is the most direct signal available, but it is preclinical, and its details need independent verification.
Camphor is a constituent of feverfew (Tanacetum parthenium), a traditional migraine herbal. This is an indirect link only.

Clinical Trial Evidence

Currently no related clinical trials registered.

Literature Evidence

PMID	Year	Type	Journal	Key Findings
42849823	2026	Preclinical (animal model)	J Ethnopharmacol	Natural (+)-camphor alleviated reserpine-induced migraine with local cerebral vasospasm in an animal model, via the p38β MAPK/ATF2 pathway
35856604	2022	Case series	Headache	Five cluster headache cases linked to toothpastes containing pro-convulsant essential oils
34373243	2021	Case report	BMJ Case Rep	Two cluster headache cases temporally related to toothpastes containing camphor and eucalyptus oils
27324458	2016	Analytical chemistry	Biomed Chromatogr	Method for measuring camphor content in feverfew essential oil; not a clinical study
27058833	2016	Review	Z Kinder Jugendpsychiatr Psychother	Historical review of paediatric neuropsychopharmacology; not relevant to camphor

Other retrieved papers for this prediction were not relevant, including feverfew anticancer assays and a zolmitriptan formulation study.

Australia Market Information

ARTG Number	Product Name	Dosage Form	Approved Indication
ARTG 11707E	Goanna Heat Cream	Cream 20%-5%-3.5%-3%-1%-1%-0.5%-0.5%-0.15%, 100 g	Not recorded

Safety Considerations

Please refer to the TGA-approved Product Information (PI) for safety information.

Points from the compiled evidence that deserve attention:

Camphor has known neurotoxicity, including seizure risk, at higher exposures. This argues for caution in any neurological indication.
Case reports describe cluster headache temporally linked to camphor-containing essential oils, so camphor may act as a headache trigger in some people.
An animal toxicity study of edible camphor reported oxidative stress and histopathological changes (relevant to oral use, not topical).

Other Predictions Reviewed

The remaining top-ranked predictions have no meaningful support and are all on Hold:

Predicted Indication	TxGNN Score	Evidence Level	Comment
Migraine with brainstem aura	0.9979	L5	Prediction only
Erectile dysfunction	0.9979	L5	Only a rat toxicity study; a possible safety signal, not efficacy
Pulmonary hypertension	0.9977	L5	Literature hits are a name collision with the CAMPHOR questionnaire, unrelated to the drug
Kyphoscoliotic heart disease	0.9970	L5	No literature or trials
Ulerythema ophryogenesis	0.9960	L5	No literature or trials
Raynaud disease	0.9956	L5	Only an unrelated outcome-measure paper
Atrophoderma vermiculata	0.9954	L5	No literature or trials
Tourette syndrome	0.9946	L5	No literature or trials; neurotoxicity concerns

Conclusion and Next Steps

Decision: Hold

Rationale: Evidence for migraine is limited to one animal study, anecdotal case reports (which describe camphor as a possible trigger of a different headache disorder) and a model prediction. There are no human trials, and neurotoxicity is a recognised concern. The prediction is best treated as a research question.

To proceed, the following is needed:

Product Information warnings and contraindications for the Australian product (currently missing)
Approved indication text for the ARTG entry
Mechanism of action data (for example from DrugBank)
Verification of the 2026 animal study, including mechanism and effect size
Human safety and pharmacokinetic data for topical or inhaled camphor in headache populations
A pilot clinical study design, if the preclinical findings are confirmed, with seizure and neurotoxicity monitoring
Disclaimer

This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.