Camphor

What it is

Camphor is a bicyclic monoterpene ketone. It occurs naturally in plants and is also made by chemical synthesis; the camphor in US over-the-counter rubs is labelled as synthetic camphor. A review of its chemistry describes it as "a bicyclic monoterpene ketone" and covers "methods of obtaining it from natural sources as well as through chemical synthesis". In the United States it is one of only two ingredients the FDA's over-the-counter antitussive monograph allows for topical use, the other being menthol.

What the research says

For the topical cough use the human evidence is thin and comes from trials of a combination rub rather than camphor on its own; a narrative review of the best-studied product calls the evidence for upper respiratory symptoms "limited and inconclusive", and a bibliometric survey of the indexed literature found only 15 clinically relevant human papers and made no recommendation while also calling these agents potentially effective. There is no randomised trial of camphor alone for cough or for muscle and joint pain in anything we reached, and the analgesic evidence for camphor by itself is a mouse study. What is far better documented is the harm side: swallowed camphor causes seizures in small children and in adults, and that literature is case reports rather than trials. Laboratory work on recombinant channels shows camphor acts on TRPV1 and TRPV3, which is the explanation offered for its warming, counterirritant feel on skin.

Evidence grade: Limited evidence.

How it works

Drug class: Monoterpene ketone used topically as an over-the-counter antitussive (cough suppressant) and external analgesic / counterirritant; an agonist of the TRPV1 and TRPV3 ion channels

Camphor acts on temperature-sensing ion channels. Patch-clamp recordings in cultured human kidney cells made to express the TRPV1 channel show camphor switches it on and then strongly desensitises it - the same channel that responds to capsaicin and to noxious heat - and the authors of that work give this as the explanation for camphor's long-standing use as a counterirritant, anti-itch and local anaesthetic agent. That is a recombinant-channel experiment: there is no skin, no sensory neurone and no person in it, so the step from the channel to what is felt on skin is inferred rather than measured. (Source 1)

What it is used for

• One randomised trial of a camphor-menthol-eucalyptus vapour rub in 138 children found parents rated the rub better than no treatment for night-time cough, but it tested the combination product, was only one night long and used parent-reported outcomes. A narrative review of that product concludes the upper-respiratory evidence is limited and inconclusive. Evidence: limited. (Source 2)
• This use rests on the counterirritant sensation rather than on outcome trials. A bibliometric survey of one PubMed search covering 2010 to 2022 found only 15 clinically relevant human papers out of 103 records on camphor- and menthol-containing topical agents, after excluding non-human work, misuse and ingestion reports and intraoral, intranasal and ophthalmic products, and its authors made no recommendation while also calling the agents potentially effective. The analgesic effect of camphor on its own has been shown in mice, not in a randomised human trial. Evidence: limited. (Source 3)
• Off-label. A narrative review found only two studies on this use and judged the evidence limited and inconclusive. Evidence: limited. (Source 4)

Interactions

• Alcohol (theoretical): We found no clinical trial, pharmacokinetic study or case report of an interaction between topical camphor and alcohol. The gap reflects how little this route has been studied rather than a demonstrated absence of interaction: one PubMed search covering 2010 to 2022 retrieved 103 records on topical camphor- and menthol-containing agents, of which 15 were clinically relevant human papers, after excluding non-human studies, misuse and ingestion reports and intraoral, intranasal and ophthalmic products. (Source 3)
• Phenobarbital and phenytoin, as treatment for camphor-induced seizures (theoretical): In rats, seizures caused by camphor did not respond to phenobarbital or phenytoin, while diazepam and propofol did control them. This is animal evidence about treating camphor poisoning, not about taking camphor alongside an anticonvulsant. (Source 5)
• Menthol and eucalyptus oil in the same product (label): Camphor is almost never sold alone in a US cough rub: the leading label combines camphor 4.8% with eucalyptus oil 1.2% and menthol 2.6%. That matters for reading the evidence, because the trials and the ferret study tested the mixture, so no human trial isolates camphor's own contribution. (Source 6)
• Dietary supplements (theoretical): We found no human study of an interaction between topical camphor and any dietary supplement. A 2024 review states that camphor's interactions with other medicinal substances have been reviewed, but it describes no quantified human supplement interaction, so the honest answer is that this has not been studied. (Source 7)

Stopping it

• We found no literature on dependence, withdrawal, rebound or tapering for topical camphor. The safety literature is instead about acute poisoning and misuse, and the reviewers' advice is framed as avoiding misuse rather than as managing discontinuation. (Source 4)
• In the one randomised trial, the rub was given as a single application and symptoms improved in every group including no treatment, so nothing in that trial speaks to stopping after repeated use. (Source 2)

What goes wrong

Swallowed camphor caused repeated generalised tonic-clonic seizures in a one-year-old child, who needed intensive care. (Source 8)

• Case report, Very low certainty.
• Size: 1 child.
• Who: a one-year-old boy who swallowed camphor tablets, Dominican Republic.
• How long: single admission.
• Result: Presented postictal after generalised tonic-clonic seizures at home with further seizures in hospital; seizures controlled with intravenous diazepam, then levetiracetam, managed in paediatric intensive care; head CT normal.
• Funding: not stated.

A one-year-old male was admitted to the Dr. Hugo Mendoza Pediatric Hospital in Santo Domingo, Dominican Republic, after ingesting camphor tablets. He presented in a postictal state following generalized tonic-clonic seizures at home, with further seizures occurring in the hospital.

In a case report of an adult who swallowed about 500 mL of camphor oil, repeated generalised tonic-clonic seizures required intubation and intensive care; the authors of that report state that camphor can be lethal to infants and children even in very small concentrations and that seizures can begin within five minutes of exposure. (Source 9)

• Case report, Very low certainty.
• Size: 1 adult (61 years) who swallowed about 500 mL of camphor oil.
• Who: one adult emergency presentation after intentional ingestion by a man with major depressive disorder; this report contains no paediatric and no low-dose data.
• How long: 48 hours of ventilation and intensive care.
• Result: At least three tonic-clonic seizure episodes are described: two at home, one in the emergency department, and a further one during the emergency-room stay before intubation. Also confusion, agitation, diaphoresis, borderline QT and QRS on the ECG, intubation, and extubation at 48 hours.
• Funding: not stated.

Limit of this finding: The paediatric statement in this report is the authors' own general assertion in their discussion, not an observation from the case, and the report gives no reference for it - the patient was a 61-year-old adult who drank about 500 mL. The seizure count is also loose as printed: the abstract describes two episodes at home, one in the emergency department, and then "another" during the emergency-room stay, which may be a re-description of the same event, so the honest count is at least three.

Camphor, being the most cultivated essential oil, is a highly toxic compound that, even in very small concentrations, can be lethal to infants and children. It is a component of numerous over-the-counter remedies and has the potential for accidental consumption. Generalized tonic-clonic seizure being the most prominent manifestation which can occur as early as five minutes after exposure needs to be anticipated and treated accordingly.

A toddler developed generalised tonic-clonic seizures after swallowing camphor, a product the report notes parents and physicians often treat as harmless. (Source 10)

• Case report, Very low certainty.
• Size: 1 child (2 years)
• Who: a two-year-old girl after oral camphor ingestion.
• How long: single admission.
• Result: Generalised tonic-clonic seizures soon after ingestion.
• Funding: not stated.

Camphor which is considered an innocent drug by parents and physicians is a common household item which can lead to severe poisoning in children even when taken in small amounts. Neurotoxicity in the form of seizures can ocur soon after ingestion.

Camphor neurotoxicity is documented in adults as well as children, including after deliberate swallowing of a large amount for a self-treated complaint. (Source 11)

• Case report, Very low certainty.
• Size: 1 adult.
• Who: an adult who voluntarily ingested camphor in India.
• How long: single admission.
• Result: Acute central nervous system effects; the report states adult ingestion is rare compared with children.
• Funding: not stated.

Camphor, a common aromatic hydrocarbon, is known to be potentially hazardous due to its acute harmful effects primarily on the central nervous system.

A review of the published complications of a camphor-containing rub collected case reports of lipid pneumonia, eye injury, camphor toxicity, skin reactions, psychosis and respiratory distress, mostly after misuse such as heating, swallowing or putting it in the nose. (Source 4)

• Expert review, not systematic, Low certainty.
• Size: 37 included articles; 11 lipid pneumonia, 5 ocular injury, 5 camphor toxicity, 3 dermatological, 1 psychosis, 1 respiratory distress.
• Who: humans reported in the medical literature.
• How long: not applicable.
• Result: Reported complications included multi-organ failure, ocular evisceration and severe pneumonia.
• Funding: not stated.

Six groups collate case reports that describe VVR-related complications, including VVR-associated lipid pneumonia (n = 11), ocular injury (n = 5), camphor toxicity (n = 5), dermatological conditions (n = 3), psychosis (n = 1), and respiratory distress (n = 1).

In the randomised vapour-rub trial, skin and mucous-membrane irritation was more common in the children given the rub than in the other groups. (Source 2)

• Randomized trial, Low certainty.
• Size: 138 children.
• Who: children aged 2 to 11 years.
• How long: one night of treatment.
• Result: The trial reports irritant adverse effects as more common among vapour-rub-treated participants; no rates are given in the abstract.
• Funding: listed as Research Support, Non-U.S. Gov't and Research Support, N.I.H., Extramural.

Irritant adverse effects were more common among VR-treated participants.

In rats, injected camphor reliably produced generalised seizures that did not respond to phenobarbital or phenytoin, although diazepam and propofol controlled them. (Source 5)

• Animal study, Very low certainty.
• Size: male Wistar rats (number not stated in the abstract)
• Who: rats given camphor 470 mg/kg intraperitoneally.
• How long: 30 minutes of electrocorticographic recording.
• Result: Six behavioural stages progressing to generalised clonic seizures with loss of postural reflexes; seizures refractory to phenobarbital and phenytoin.
• Funding: grant-supported (grants list present)

Evaluation of anticonvulsant efficacy demonstrated that camphor-induced seizures were refractory to phenobarbital and phenytoin, whereas diazepam and propofol significantly reduced β- and γ-band power and effectively controlled convulsive activity.

In excised and living ferret airway, a camphor-menthol-eucalyptus rub increased mucin secretion and slowed the cilia in tissue, while raising mucus transport velocity in airways already inflamed with endotoxin; the authors say this pattern resembles irritant exposure and may lead to mucus obstruction of small airways. (Source 12)

• Animal study, Very low certainty.
• Size: tracheas from 15 healthy ferrets plus anaesthetised ferrets.
• Who: ferret trachea, in vitro and in vivo, with and without endotoxin-induced inflammation; prompted by a toddler who developed respiratory distress after the rub was applied under her nose.
• How long: acute exposure.
• Result: Mucin secretion increased by 63% over controls in vitro (p < 0.01); ciliary beat frequency fell by 35% (p < 0.05); in endotoxin-inflamed airways mucociliary transport velocity rose 34% (p = 0.002). The harm inference is the authors' own and is conditional - the findings "may lead to" mucus obstruction and increased nasal resistance, which was not measured here.
• Funding: not stated.

¹ Mucin secretion was increased by 63% over the controls in the VVR in vitro group (p < 0.01). CBF was decreased by 35% (p < 0.05) in the VVR group.

The same monograph requires camphor ointments to carry an external-use-only warning and, in bold, a warning not to heat, microwave or add the product to hot water because it may splatter and cause burns. (Source 13)

• Official position, Certainty not rated.
• Size: not applicable.
• Who: US over-the-counter products containing camphor.
• How long: text as printed in the 2024 CFR edition.
• Result: Required warnings include "For external use only. Do not take by mouth or place in nostrils.", a flammability signal word with "Keep away from fire or flame." where one applies, and the bold burn warning. These are the warnings the monograph's own directions cross-refer to, and the monograph requires that cross-reference to appear first under "Directions".
• Funding: not applicable.

“When using this product, do not [bullet] heat [bullet] microwave [bullet] add to hot water or any container where heating water. May cause splattering and result in burns.” [Information highlighted in bold type.]

What the evidence supports

In one randomised trial, parents rated a camphor-menthol-eucalyptus vapour rub better than no treatment for their child's night-time cough, congestion and sleep difficulty, and better than plain petrolatum for cough severity. (Source 2)

• Randomized trial, Low certainty.
• Size: 138 children who completed the trial.
• Who: children aged 2 to 11 years with cough and congestion from an upper respiratory tract infection. The abstract names only "vapor rub"; that the rub was the camphor-menthol-eucalyptus product is taken from the trial's own full text and from the marketed label, not from the quoted abstract. 144 children were enrolled and 138 completed.
• How long: two consecutive nights, a single application on the second night.
• Result: Pairwise comparisons favoured the vapour rub over no treatment for all outcomes except rhinorrhoea, and over petrolatum for cough severity, child and parent sleep difficulty and combined symptom score; petrolatum was not significantly better than no treatment for any outcome. No absolute effect sizes are given in the abstract.
• Funding: listed as Research Support, Non-U.S. Gov't and Research Support, N.I.H., Extramural.

Pairwise comparisons demonstrated the superiority of VR over no treatment for all outcomes except rhinorrhea and over petrolatum for cough severity, child and parent sleep difficulty, and combined symptom score. Petrolatum was not significantly better than no treatment for any outcome.

In mouse models of nerve-injury and chemotherapy pain, camphor reduced pain behaviour and lowered the firing rate of sensory neurons; this is animal work, not a human finding. (Source 14)

• Animal study, Very low certainty.
• Size: mice (number not stated in the abstract)
• Who: paclitaxel, oxaliplatin, chronic constriction injury and streptozotocin mouse neuropathic pain models.
• How long: not stated.
• Result: Camphor significantly reduced flinching and licking time across the four models and reduced action-potential firing frequency in dorsal root ganglion neurons; unlike pregabalin it did not impair locomotor or rotarod performance.
• Funding: not stated.

Compared with vehicle group, camphor significantly reduced the flinching and licking time in neuropathic pain model mice, including PTX, OXA, STZ and CCI induced peripheral neuralgia models.

The US FDA's over-the-counter antitussive monograph, as codified in the 2024 Code of Federal Regulations, lists camphor as one of only two permitted topical antitussive active ingredients and sets the ointment at 4.7 to 5.3 percent camphor. (Source 15)

• Official position, Certainty not rated.
• Size: not applicable.
• Who: US over-the-counter products.
• How long: monograph first issued 52 FR 30055, Aug. 12, 1987, as amended to 67 FR 4907, Feb. 1, 2002; text as printed in the 2024 CFR edition.
• Result: Concentration range 4.7 to 5.3 percent camphor in a suitable ointment vehicle, rubbed on throat and chest in a thick layer, up to three times daily, with children under 2 years told to ask a doctor. A separate subparagraph sets 6.2 percent camphor for steam inhalation. The directions must open with a bold cross-reference to the warnings printed under "When using this product".
• Funding: not applicable.

The product contains 4.7 to 5.3 percent camphor.

What the evidence does not support

A narrative review of the medical literature on the best-studied camphor-containing rub judged the evidence for treating upper respiratory infection symptoms and nail fungus to be limited and inconclusive. (Source 4)

• Expert review, not systematic, Low certainty.
• Size: 37 articles meeting inclusion criteria out of a pool of 220.
• Who: humans using Vicks VapoRub, all indications.
• How long: not applicable.
• Result: Seven articles addressed upper respiratory tract infection symptoms, two onychomycosis and two wound care; six groups collated case reports of complications.
• Funding: not stated.

The evidence around the use of VVR for the treatment of URTI symptoms and onychomycosis is limited and inconclusive.

A bibliometric survey of the indexed clinical literature on topical camphor- and menthol-containing agents found very few human studies, judged the agents potentially effective across pain, cold symptoms and itch, and reached no recommendation on their use. (Source 3)

• Survey study, Low certainty.
• Size: 103 PubMed records retrieved, of which 15 (14.6%) were clinically relevant.
• Who: published papers rather than people: peer-reviewed English-language articles indexed in PubMed from 2010 to 2022 on camphor- and menthol-containing compounds.
• How long: not applicable.
• Result: 15 of 103 retrieved records concerned treatment of a health disorder. The search covered one database over 2010 to 2022 only and excluded non-research articles, articles not involving human subjects, reports of improper application or misuse including ingestion, and all intraoral, intranasal and ophthalmic agents. The authors' own conclusion runs both ways: the agents are "potentially effective at treating pain, upper respiratory infection symptoms, and pruritus" and at the same time no definitive recommendation can be made.
• Funding: not stated.

Limit of this finding: Two things to hold in mind about this count. It is one PubMed search over one 13-year window with wide exclusions, so 15 is a floor for the literature, not a census of it. And the same authors state both halves of the position - that these agents are potentially effective and that the studies are too few to recommend them - so quoting only the cautious half would misrepresent them.

However, with a limited number of studies addressing these compounds' uses in each application, no definitive recommendation can be made regarding their use.

In a small Cambodian study, no camphor was detectable in the whole blood of any of the 19 infants assayed, most of whom were current users of a camphorated balm, so the hypothesis that topical camphor was driving their rapid breathing was not supported. (Source 16)

• Case-control study, Very low certainty.
• Size: 19 infants assayed (9 tachypnoeic, 10 healthy controls)
• Who: Cambodian infants in Prey Veng province; present use of Tiger Balm was reported for 8 of 9 (88.9%) tachypnoeic infants and 7 of 10 (70%) healthy controls, so 4 of the 19 assayed were not current users.
• How long: single assessment.
• Result: No detectable camphor in any case or control. This is a null at the assay's detection limit, not a measured zero, and the paper records no time between last application and blood draw.
• Funding: not stated.

Eight (88.9%) mothers of tachypneic infants and 7 (70%) mothers of healthy infants reported presently using Tiger Balm on their child (P = .36).

The same study reports that none of the infants, sick or healthy, had any detectable camphor in the blood. (Source 16)

• Case-control study, Very low certainty.
• Size: 19 infants (9 tachypnoeic, 10 healthy controls)
• Who: Cambodian infants assessed for Tiger Balm use and whole-blood camphor.
• How long: single assessment on stored frozen samples.
• Result: No case subject and no healthy control subject had detectable camphor. The authors' own conclusion is narrow: that camphor is unrelated to the tachypnoeic illness in these children.
• Funding: the authors state they received no financial support for the research, authorship or publication.

No case subject and no healthy control subject had any detectable camphor in the blood.

Where the research disagrees

Whether the topical cough use of camphor is supported by evidence or mainly by long custom and a regulatory monograph

• US FDA, over-the-counter antitussive monograph as codified in the 2024 CFR, regulatory position, monograph first issued 1987 and last amended 2002: "(b) Topical antitussives. (1) Camphor. (2) Menthol." - camphor is listed as a permitted topical antitussive active ingredient at 4.7 to 5.3 percent in an ointment vehicle (Source 17)
• Authors of a 2023 bibliometric review of the clinical literature, bibliometric survey of 103 indexed papers, of which 15 were clinically relevant human studies: "However, with a limited number of studies addressing these compounds' uses in each application, no definitive recommendation can be made regarding their use." (Source 3)
• Authors of a 2025 narrative review of the best-studied camphor-containing product, narrative review of 37 included articles from a pool of 220: "The evidence around the use of VVR for the treatment of URTI symptoms and onychomycosis is limited and inconclusive." (Source 4)

How much

• Reference intake: There is no prescriber-set dose: this is an over-the-counter product whose amount is fixed by the Drug Facts label. The US FDA monograph position, as printed in 21 CFR 341.74(d)(2)(i) in the 2024 Code of Federal Regulations, is that a camphor ointment for cough contains 4.7 to 5.3 percent camphor, is rubbed on the throat and chest in a thick layer, used up to three times daily, and is not for children under 2 years without a doctor. (Source 15)
• Upper limit: There is no systemic daily maximum for the topical route. The marketed US label for the leading product states camphor (synthetic) 4.8%, directs that it not be used in children under 2 years, and for the muscle-and-joint use says to apply to the affected area not more than 3 to 4 times daily. (Source 6)
• Studied: The randomised paediatric trial gave a single bedtime application of vapour rub ointment to the child's chest and neck. (Source 2)
• Studied: The rat seizure study gave camphor 470 mg/kg intraperitoneally, a route and amount with no counterpart in human topical use. (Source 5)

A common belief, and what the research shows

The belief: Camphor is a gentle traditional remedy, so a camphor rub or camphor block is safe to have around small children.

What the research shows: The poisoning literature says the opposite about swallowing it. A case report states that camphor “is a highly toxic compound that, even in very small concentrations, can be lethal to infants and children”, and a paediatric case report of a one-year-old notes that “even small ingested doses can lead to life-threatening symptoms”. The US label's own instructions are “Do not use by mouth in nostrils on wounds or damaged skin with tight bandages” and “If swallowed, get medical help or contact a Poison Control Center right away.”

Questions and answers

What is it?

Camphor is a bicyclic monoterpene ketone - a waxy, strong-smelling solid. It occurs naturally in plants and is also made by chemical synthesis; US cough rubs list it as synthetic camphor. In the United States it is one of only two ingredients the over-the-counter antitussive monograph allows for topical use, the other being menthol. (Source 17)

What does it do in the body?

Camphor acts on temperature-sensing ion channels in sensory nerves. Patch-clamp recordings in cultured cells engineered to carry TRPV1 show camphor switches that channel on and then strongly desensitises it - the channel that also responds to chilli heat and to painful heat - and that is the explanation offered for why camphor feels warming, reduces itch and has a numbing, counterirritant quality. That work is a recombinant-channel experiment with no skin and no sensory neurone in it, so the step from channel to sensation is inferred. (Source 1)

Is it good or bad for you?

It depends entirely on route. Rubbed on unbroken skin at monograph strength it is tolerated by most people, with skin irritation the usual complaint; swallowed, it is dangerous, and seizures have followed small amounts in young children. The one randomised trial of a camphor-containing rub also reported more irritant side effects in the treated children than in the comparison groups. (Source 2)

How do you get more of it?

Camphor is a medicine, not a nutrient, so there is no reason to try to get more of it. What the monograph describes is a fixed concentration in a product: 4.7 to 5.3 percent camphor in an ointment rubbed on the throat and chest, up to three times daily, with children under 2 years told to ask a doctor. That is a description of the regulation, not a recommendation. (Source 15)

If it is harmful, what reduces it?

For skin exposure, stopping the product is the intervention described; for swallowed camphor, the published management is urgent medical care and supportive treatment, with seizures treated with benzodiazepines. In the reported cases, seizures were controlled with intravenous diazepam and the child recovered in intensive care. There is no antidote in this literature. (Source 8)

Why might someone be low in it or missing it?

Does not apply in the usual sense. Camphor is not a nutrient and the body does not need it, so no one is deficient in it; the only way to be "low" in camphor is not to use a camphor-containing product. How much crosses intact skin is a separate and unsettled question: the same Cambodian paper that found no detectable blood camphor also notes that repeated or prolonged skin exposure can produce symptomatic blood levels, that camphor from skin patches peaks about 4 hours after application and is undetectable within 8 to 12 hours, and that it did not record how long before the blood draw the balm had last been applied. A null level at an unrecorded time therefore says nothing about absorption. (Source 18)

Which whole foods contain it or feed it?

No whole food is a source of medicinal camphor, and camphor is not eaten in the amounts used in rubs. A 2024 review of camphor describes how it is obtained from natural sources and by chemical synthesis and discusses its use in industrial preparations - that is, it is an industrial and pharmaceutical ingredient rather than a dietary one. (Source 7)

What happens if you do not have it?

Nothing happens: there is no camphor deficiency state. Not using a camphor rub simply means not having whatever symptomatic relief it offers, and the published assessment of that relief is that the evidence is limited and inconclusive. (Source 4)

How can you test for it?

There is no routine clinical test, and none is needed for ordinary topical use. Camphor can be measured in whole blood in a research setting, as in the Cambodian infant study, where no infant had a detectable level; product camphor content can be quantified in the laboratory. No validated diagnostic test for camphor exposure in a person is described in the literature we searched, and none of the poisoning case reports we read used a blood camphor level to make the diagnosis. (Source 16)

We searched: Europe PMC searches for camphor combined with pharmacokinetics, percutaneous absorption, blood concentration and poison-centre data; and the camphor toxicity case reports, none of which used a blood camphor level to make the diagnosis.

References

1. Anesthesiology. Pore helix domain is critical to camphor sensitivity of transient receptor potential vanilloid 1 channel. 2012. PMID 22314297, DOI 10.1097/aln.0b013e318249cf62. Read the source
2. Pediatrics. Vapor rub, petrolatum, and no treatment for children with nocturnal cough and cold symptoms. 2010. PMID 21059712, DOI 10.1542/peds.2010-1601. Read the source
3. Cureus. Looking Back to Move Forward: The Current State of Research on the Clinical Applications of Camphor- and Menthol-Containing Agents. 2023. PMID 37546095, DOI 10.7759/cureus.41426. Read the source
4. PeerJ. There's the Rub: a narrative review of the benefits and complications associated with Vicks VapoRub use. 2025. PMID 40034673, DOI 10.7717/peerj.19105. Read the source
5. Neurotoxicity research. Camphor-Induced Seizures in Rats Increase the Potency of Gamma Oscillations During the Ictal Period, A Component that may Lead to Refractoriness in Seizure Control. 2026. PMID 41874845, DOI 10.1007/s12640-026-00793-3. Read the source
6. DailyMed (US National Library of Medicine); labeler Procter & Gamble, Cincinnati OH; NDC 58933-544. VICKS VAPORUB (camphor (synthetic), eucalyptus oil, and menthol) ointment - US Drug Facts label, sections Active ingredients through Other information, including the Purpose section whose heading the labeler mis-typed as "Inactive ingredients Purpose". 2026. Read the source
7. Pharmaceuticals (Basel, Switzerland). Is Camphor the Future in Supporting Therapy for Skin Infections?. 2024. PMID 38931382, DOI 10.3390/ph17060715. Read the source
8. BMC pediatrics. From cultural remedy to medical emergency: a case report of camphor toxicity in a one-year-old male patient. 2025. PMID 39979814, DOI 10.1186/s12887-025-05488-w. Read the source
9. Cureus. Camphor Oil Toxicity: A Case Report. 2023. PMID 38022187, DOI 10.7759/cureus.47412. Read the source
10. Turk pediatri arsivi. Seizures due to high dose camphor ingestion. 2015. PMID 26884696, DOI 10.5152/turkpediatriars.2015.1360. Read the source
11. The National medical journal of India. Camphor poisoning in an adult: Seizures manifesting as 'mis-purposed' drug effect. 2024. PMID 39096231, DOI 10.25259/nmji_2_21. Read the source
12. Chest. Vicks VapoRub induces mucin secretion, decreases ciliary beat frequency, and increases tracheal mucus transport in the ferret trachea. 2009. PMID 19136404, DOI 10.1378/chest.08-0095. Read the source
13. US Government Publishing Office, Code of Federal Regulations. 21 CFR 341.74(c)(5) Warnings for topical antitussives containing camphor or menthol - subparagraphs (i)-(vi) and the bullet-symbol footnote, 2024 annual edition. 2024. Read the source
14. Journal of pain research. Camphor Attenuates Hyperalgesia in Neuropathic Pain Models in Mice. 2023. PMID 36925623, DOI 10.2147/jpr.s398607. Read the source
15. US Government Publishing Office, Code of Federal Regulations. 21 CFR 341.74(d) Directions for antitussive drug products - paragraph (d) lead-in, (d)(1)(i)-(v) oral antitussives and (d)(2)(i)-(iii) topical antitussives containing camphor or menthol (ointment and lozenge), 2024 annual edition. 2024. Read the source
16. Global Pediatric Health. No Camphor Toxicity in Cambodian Infants - Results, the Tiger Balm use paragraph and the camphor assay result. 2017. PMID 28491925, DOI 10.1177/2333794X17702980. Read the source
17. US Government Publishing Office, Code of Federal Regulations (2024 edition), Title 21 Volume 5. 21 CFR 341.14 Antitussive active ingredients - whole section, 2024 annual edition. 2024. Read the source
18. Global Pediatric Health. No Camphor Toxicity in Cambodian Infants - Discussion, the two consecutive paragraphs on camphor blood concentrations after dermal exposure and on the study's limitations. 2017. PMID 28491925, DOI 10.1177/2333794X17702980. Read the source