Essential Oils & Aromatherapy · Essential oil
Citronella Oil
Cymbopogon nardus and Cymbopogon winterianus · also called Citronella essential oil, oil of citronella, Ceylon citronella oil, Java citronella oil
Citronella oil is a grassy-smelling oil distilled from the leaves of two tropical grasses. It is mostly used to keep mosquitoes away. Studies suggest it protects for a shorter time than DEET. The oil can irritate skin or cause an allergy, and it should never be swallowed or kept where children or pets can reach it.
General information, not medical advice. Last substantive update · Not medically reviewed. A named clinician has not signed off on this page. How this page is made
About Citronella Oil
Citronella oil is a repellent, not a remedy. Reviews suggest it protects for a shorter time than DEET and that effects depend on the product. It is an irritant and possible allergen, and swallowing it or breathing it into the lungs can be dangerous.
Safety first
Do not swallow citronella oil. Poison Control warns that essential oils can cause serious poisoning and that oil breathed into the lungs can cause pneumonia. Children have thin skin and immature livers and may be more vulnerable. Keep bottles locked away from children and pets. Lamp and torch fuels are a separate, known danger to toddlers, so keep them apart from essential oils.
The oil can irritate skin and eyes, and it may cause a skin allergy. Patch tests have found citronella among nine essential oils with more than 2 percent positive reactions in people suspected of contact allergy. A mouse test was negative, so the evidence is mixed. Do not use it undiluted, and do not use it on broken skin. Stop if a rash appears.
Pets, especially cats, are at risk from essential oils in general. Ask a vet before using any citronella product near them. If anyone may have swallowed the oil, call a poison centre or emergency services (US Poison Help: 1-800-222-1222; numbers elsewhere were not checked).
What it is
The oil is distilled from two grasses, Cymbopogon nardus and Cymbopogon winterianus. It is yellow to brown with a grassy or floral smell. Its main parts are citronellal, citronellol and geraniol, and the mix varies by grass variety. A minor part, methyleugenol, is described by US authorities as reasonably anticipated to be a human carcinogen, so EFSA asks that people who handle the oil limit exposure.
NPIC says the oil repels insects rather than killing them, by masking scents that attract them. The US EPA lists oil of citronella as an ingredient in registered skin repellents (three products, against more than 500 for DEET) and in unregistered exempt products.
What the research shows
The best recent source, a 2026 review of 19 human studies, found natural repellents such as citronella usually gave two to four hours of complete protection. DEET products often gave five to nine. A 2002 lab test found most plant repellents protected for under 20 minutes. A 2019 review of 62 trials ranked citronella among the best plant repellents against Anopheles, but its very long times do not match the human-study review.
Candles and incense help only a little and only nearby. We found no trial of citronella scent for mood, sleep or pain, and no evidence that it prevents disease. The EPA says a registration number means the company gave effectiveness information, and that CDC recommends registered products (CDC page not read).
At a glance
Traditional uses history, not proof
- Keeping mosquitoes away (sprays, lotions, candles, torches)
- Scent and food flavouring in small amounts
Studied for research
- Mosquito repellent on skin: low certainty, shorter protection than DEET
- Candles, incense and diffusers: low certainty, modest effect close by
- Preventing mosquito-borne disease: no evidence
- Scent for mood, sleep or pain: no trial found
Main compounds
- Citronellal
- Citronellol
- Geraniol
- Methyleugenol (minor)
Common forms
- Essential oil, distilled from the leaves
- Repellent sprays and lotions
- Candles, incense and diffusers
Research links: US EPA: skin-applied repellent ingredients · NPIC: oil of citronella fact sheet · Poison Control: essential oils · Research Library · Genes & Biomarkers Library
What it is and its history
- Accepted scientific name
- Cymbopogon nardus (L.) Rendle and Cymbopogon winterianus Jowitt ex Bor; the oil is distilled from the leaves of these grasses
- Naming authority
- Both names are ACCEPTED in the GBIF backbone (usage keys 2705267 and 2705273), checked 2026-10-25.
- Common names
- Citronella oil (English); Ceylon citronella oil (English); Java citronella oil (English); Oil of citronella (English)
- Family or group
- Poaceae (grass family)
- Native range
- Not verified.
- Habitat
- Not verified.
- Cultivation
- Not verified.
- Harvest and processing
- NPIC says the oil is distilled from two grass varieties; EFSA describes oil from the leaves. Other details not verified.
- Look-alikes and adulterants
- Name: Lemongrass oil (Cymbopogon citratus or flexuosus); Note: A close relative that EFSA assessed separately; a skin allergy review lists lemongrass oil (Cymbopogon schoenanthus) as a frequent sensitiser. Not the same oil.; Name: Citronella-scented geranium; Note: A different garden plant used for the same idea; not the source of this oil.; Name: Lamp and torch fuels; Note: These are fuels, not essential oils, and are poisonous if swallowed.
- Sustainability and conservation
- Not verified.
Photographs
Traditional use and history history, not clinical proof
| Tradition or era | Documented use | Source |
|---|---|---|
| United States regulation | Oil of citronella was first registered in the US in 1948, according to NPIC, and is also used as a food flavouring. | s-npic-citronella |
| Older traditional use | Not verified. No source we read describes traditional use. | none |
Traditional use shows how it was used. It does not show that it works or is safe today.
What is inside, and how it may work
What it contains and how those compounds act in cells and animals. Laboratory and animal mechanisms are not proven effects in people.
Main compounds
| Compound | Family | Where it is concentrated | Activity studied | Level of evidence |
|---|---|---|---|---|
| Citronellal PubChem 7794 | Monoterpenoid aldehyde | Leaf oil A main component; percentages not read. | Named by NPIC as a main component. 15 | Authoritative guidance |
| Citronellol PubChem 8842 | Monoterpenoid alcohol | Leaf oil A main component; percentages not read. | Named by NPIC as a main component. 15 | Authoritative guidance |
| Geraniol PubChem 637566 | Monoterpenoid alcohol | Leaf oil A main component; percentages not read. | A main component. In a mouse test geraniol itself was a skin sensitiser. In candle and diffuser trap tests geraniol repelled more mosquitoes than citronella. 15 10 13 | Mouse and field test |
| Methyleugenol PubChem 7127 | Phenylpropene | Leaf oil (minor) A minor component; percentages not read. | Reasonably anticipated to be a human carcinogen by the US Department of Health and Human Services, per NPIC; EFSA asks that handlers' exposure be minimised. 15 5 | Authoritative guidance |
Mechanisms, receptors and pathways
| Target or pathway | Gene or receptor | What was found | Level |
|---|---|---|---|
| Insect behaviour | Not established | NPIC says the oil repels rather than kills by masking scents that attract insects. A 2023 review says the exact mode of action, molecular targets and smell and taste receptors involved are not well known. 15 1 | Theory review |
| Evaporation on skin | Not applicable | Plant oils evaporate quickly from skin, shortening protection, so products use special vehicles such as encapsulation and nanoemulsions. 1 18 | Review |
| Skin sensitisation | Not applicable | In mice the oil was negative while some components were positive; in human patch tests the oil was among those with more than 2 percent positive results. 10 22 | Mixed |
Isolated compounds versus whole extracts
In the same trap tests, geraniol alone repelled more mosquitoes than citronella products, so the whole oil is not clearly the best form of its own main ingredient. Skin allergy findings also differ between the whole oil and its parts.
Nutritional composition
Citronella oil is not a nutrient. It is used as a food flavouring in tiny amounts, according to NPIC; this page does not suggest eating it.
2 low certainty1 very low certainty2 not enough evidence
What is Citronella Oil good for?
Citronella oil is studied for one main job: keeping mosquitoes away. Here is how strong the evidence is for each use. Safety comes first: do not swallow it, and do not put it on skin undiluted.
Benefits, one by one
Each card is a research question, not a promise. Tap a goal to filter. Open a card to see the studies, doses and limits.
Mosquito repellent on skin (protection time compared with DEET)
Low certaintyCitronella-type repellents can keep mosquitoes off for a while, but usually for a shorter time than DEET. A 2026 review of human studies found about two to four hours for natural repellents such as citronella, against five to nine hours for DEET. A 2002 laboratory test found most plant repellents protected for under 20 minutes.
7 studiesNot given. This page gives no amounts and no recipes.
Studies, doses and limits
What the trials found
One 2026 systematic review of 19 human studies (all repellents, citronella grouped with other plant oils) and one 2002 laboratory test in 15 volunteers.
Results
2026 review: natural repellents based on oils such as citronella, lemon eucalyptus, neem and lemongrass usually gave two to four hours of complete protection; DEET products often five to nine hours. 2002 test (15 volunteers): a 23.8 percent DEET product protected on average 301.5 minutes, a soybean-oil product 94.6 minutes, and all other botanical repellents under 20 minutes. The abstract does not name which botanical products were tested.
Effect sizes as reported
No citronella-only figure is given in either abstract.
Why this rating
The studies differ a lot in products and methods, citronella is grouped with other plant oils, and the two main sources disagree on how long plant repellents last.
Form and dose studied
Not given. This page gives no amounts and no recipes.
Who was studied
Adults in test settings. Not studied separately in babies or pregnancy.
Limits
Results depend on the product and how it is made. The review did not pool numbers. An erratum to the 2026 review exists and was not read.
Why researchers looked
Plant oils are popular as an alternative to synthetic repellents.
Traditional use
Citronella grasses are distilled for a scented oil used in repellents; the sources we read give no older traditional claims.
Proposed mechanism Review
NPIC says the oil repels rather than kills, by masking scents that attract insects. A 2023 review says the exact way it works is mostly theory and that the oil evaporates quickly from skin, so products often need special ingredients to last longer.
A proposed mechanism does not show that the effect happens in people.
Where mosquito-borne illness is a real risk, ask a doctor or pharmacist about repellents registered with your health authority. The US EPA says an EPA registration number means the company gave it effectiveness information.
Repelling Anopheles (malaria-carrying) mosquitoes in tests
Very low certaintyA review of 62 trials ranked citronella oil among the strongest plant repellents against Anopheles mosquitoes in test conditions. These are test results, not proof that it prevents malaria.
2 studiesNot given. This page gives no amounts and no recipes.
Studies, doses and limits
What the trials found
One 2019 systematic review of 62 trials. The abstract does not say how many were in people.
Results
The highest repellency came from a Ligusticum sinense extract, followed by citronella, pine, Dalbergia sissoo, peppermint and Rhizophora mucronata oils, with complete protection times of 9.1 to 11.5 hours across that group.
Effect sizes as reported
The 9.1 to 11.5 hour range is for the whole top group, not citronella alone.
Why this rating
The abstract does not separate people from laboratory or animal tests or say how the products were made, and the long times are far above the 2 to 4 hours seen in the 2026 human-study review.
Form and dose studied
Not given. This page gives no amounts and no recipes.
Who was studied
Not stated.
Limits
Unclear study types; no citronella-only number; published up to July 2018.
Why researchers looked
Anopheles mosquitoes carry malaria, so plant repellents are tested against them.
Traditional use
Plant repellents have a long traditional role against mosquitoes, according to the review's authors.
Proposed mechanism Review
Not established. The review does not give a mechanism.
A proposed mechanism does not show that the effect happens in people.
Not a substitute for registered repellents or for malaria advice from a clinician.
Preventing malaria, dengue or other mosquito-borne disease
Not enough evidenceWe found no study showing that citronella oil prevents any mosquito-borne illness in people.
3 studiesNot given. This page gives no amounts and no recipes.
Studies, doses and limits
What the trials found
No human study of citronella oil and infection was found in the sources read.
Results
Nothing to report. Reviews discuss bite protection time, not infection rates.
Effect sizes as reported
Not applicable.
Why this rating
No data on infection outcomes for citronella.
Form and dose studied
Not given. This page gives no amounts and no recipes.
Who was studied
Not applicable.
Limits
Bites avoided is not the same as illness avoided.
Why researchers looked
Preventing bites is the reason repellents are used.
Traditional use
Not applicable.
Proposed mechanism None
Not applicable.
A proposed mechanism does not show that the effect happens in people.
Where malaria, dengue or similar disease is a real risk, ask a doctor or travel clinic about proven protection.
Candles, incense and diffusers outdoors and indoors
Low certaintyCitronella candles cut mosquito numbers or bites a little, but not by much and only close by. Citronella was weaker than geraniol and linalool in the same tests.
4 studiesNot given. This page gives no amounts and no recipes.
Studies, doses and limits
What the trials found
Field and trap experiments only: a woodlot test with 8 people, and two trap experiments.
Results
Woodlot, 1995: bites per 5 minutes 6.2 with citronella candles, 8.2 with citronella incense, 8.2 with plain candles and 10.8 with nothing; overall reductions 42.3 percent and 24.2 percent. Trap tests: citronella candles at 1 m caught 35.4 percent fewer female mosquitoes, with the effect dropping at 2 m and 3 m. Indoors citronella candles repelled 14 percent and diffusers 68 percent; outdoors diffusers 6 m from traps repelled 22 percent. Geraniol did better than citronella in both trap studies.
Effect sizes as reported
About a quarter to two fifths fewer bites or mosquitoes, close to the product.
Why this rating
A few small, old experiments, mostly using trap catches rather than bites on people. They agree that effects are modest.
Form and dose studied
Not given. This page gives no amounts and no recipes.
Who was studied
Adults outdoors.
Limits
Small and old; trap catches are not bites; commercial products of unknown exact content.
Why researchers looked
Candles and torches are a common way people use citronella.
Traditional use
Not applicable.
Proposed mechanism None
Vapour in the air may mask the scents that mosquitoes follow; the sources do not prove how it works.
A proposed mechanism does not show that the effect happens in people.
A burning candle or torch is a fire and fume risk. Lamp and torch fuels are poisonous if swallowed, so keep them well apart from essential oils and out of children's reach.
Scent for mood, sleep or pain (aromatherapy)
Not enough evidenceWe found no human trial of citronella scent for mood, sleep or pain, so we cannot say it helps.
1 studiesNot given. This page gives no amounts and no recipes.
Studies, doses and limits
What the trials found
None found in the sources we looked at.
Results
Nothing to report.
Effect sizes as reported
Not applicable.
Why this rating
No trials found.
Form and dose studied
Not given. This page gives no amounts and no recipes.
Who was studied
Not applicable.
Limits
Absence of trials is not proof of no effect.
Why researchers looked
Essential oils are often sold as aromatherapy.
Traditional use
Not applicable.
Proposed mechanism None
Not applicable.
A proposed mechanism does not show that the effect happens in people.
Scent does not make an oil safe to swallow or put on skin undiluted.
Connections to the rest of health
How Citronella Oil connects to the rest of our health knowledge graph. Every link says what kind of connection it is. A safety link (for example to the liver) is a warning, not a benefit. A study that merely mentions a topic never creates a benefit link.
Explore every connection: goals, body systems, organs, symptoms, genes
A. Wellness goals
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Insect Protection | Low certainty | Mosquito repellent on skin (protection time compared with DEET): Citronella-type repellents can keep mosquitoes off for a while, but usually for a shorter time than DEET. A 2026 review of human studies found about two to four hours for natural repellents such as citronella, against five to nine hours for DEET. A 2002 laboratory test found most plant repellents protected for under 20 minutes. Repelling Anopheles (malaria-carrying) mosquitoes in tests: A review of 62 trials ranked citronella oil among the strongest plant repellents against Anopheles mosquitoes in test conditions. These are test results, not proof that it prevents malaria. | 6 7 1 18 20 21 15 2 11 12 13 | |
| Insect Protection | Not enough evidence | Preventing malaria, dengue or other mosquito-borne disease: We found no study showing that citronella oil prevents any mosquito-borne illness in people. | 6 2 21 | |
| Calm Relaxation | Not enough evidence | Scent for mood, sleep or pain (aromatherapy): We found no human trial of citronella scent for mood, sleep or pain, so we cannot say it helps. | 14 |
B. Body systems
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Skin | Adverse effect or risk | Documented | Skin and eye irritant and possible sensitiser. Preparation or compound: Essential oil |
5 22 |
| Integumentary System | Biological association | Low certainty | Studied for: Mosquito repellent on skin (protection time compared with DEET) Studied for: Repelling Anopheles (malaria-carrying) mosquitoes in tests | 6 7 1 18 20 21 15 2 11 12 13 |
| Immune System | Biological association | Not enough evidence | Studied for: Preventing malaria, dengue or other mosquito-borne disease | 6 2 21 |
| Nervous System | Biological association | Not enough evidence | Studied for: Scent for mood, sleep or pain (aromatherapy) | 14 |
E. Health conditions
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Allergic contact dermatitis | Mixed findings | Patch tests positive in some; mouse test negative. Preparation or compound: Essential oil |
22 10 |
I. Biomarkers
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Complete protection time | Biological association | Low certainty | Measured in trials: lengthened. A lab change is not the same as a health benefit. | 6 7 2 |
| Bites received or mosquitoes caught | Biological association | Low certainty | Measured in trials: lowered. A lab change is not the same as a health benefit. | 11 |
| Mosquitoes caught in traps near a product | Biological association | Low certainty | Measured in trials: lowered. A lab change is not the same as a health benefit. | 12 13 |
L. Active compounds
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Citronellal | Biological association | Authoritative guidance | Named by NPIC as a main component. Preparation or compound: Leaf oil |
15 |
| Citronellol | Biological association | Authoritative guidance | Named by NPIC as a main component. Preparation or compound: Leaf oil |
15 |
| Geraniol | Biological association | Mouse and field test | A main component. In a mouse test geraniol itself was a skin sensitiser. In candle and diffuser trap tests geraniol repelled more mosquitoes than citronella. Preparation or compound: Leaf oil |
15 10 13 |
| Methyleugenol | Biological association | Authoritative guidance | Reasonably anticipated to be a human carcinogen by the US Department of Health and Human Services, per NPIC; EFSA asks that handlers' exposure be minimised. Preparation or compound: Leaf oil (minor) |
15 5 |
Each connection is stored with the ingredient, the connected record, the kind of connection, the evidence status, the supporting studies, the preparation or compound involved, and a review date (last reviewed October 25, 2026).
Evidence at a glance: what changed in 2 lab markers
Tap a number to show only those markers. Counts are markers, not people.
The evidence
The research centre for Citronella Oil. Every record here was checked against PubMed or the publisher's page; we never list a study we have not verified.
Evidence by outcome
Bars show how many studies we found for each outcome, not how well it works. People are added up across trials only (reviews are not added, to avoid double counting).
How we rate evidence
High certainty
Several well-run trials or reviews agree; further research is unlikely to change the picture much.
Moderate certainty
Good trials point the same way, but some doubt remains.
Low certainty
Small, short or inconsistent trials. The finding could change with better research.
Very low certainty
Very little or very weak human data. Treat as a possibility only.
Mixed findings
Trials or reviews disagree with each other.
Not enough evidence
Not enough human research to say either way.
Evidence against
Good research found no benefit, or found harm.
We take the reviewers' own risk-of-bias and GRADE statements where they exist, and otherwise judge from study size, design, consistency, directness and whether a product matches what is sold. Many publications do not make evidence high. Method note: We started from our existing citronella summary, then read the abstract of every PubMed study cited and the EPA, NPIC, Poison Control and Pet Poison Helpline pages. The CDC page could not be opened and the NCCIH page was not re-opened; where that matters the page says so.
Study library: every study we checked 22
| Study | Design | People | Product, dose, length | Result |
|---|---|---|---|---|
| Almeida 2023 Challenges encountered by natural repellents: Since obtaining until the final product. Pesticide Biochemistry and Physiology · PMID 37666610 · DOI |
Narrative review |
Review of natural repellents (mainly essential oils) against Aedes aegypti and other vectors | Natural repellents including citronella (Cymbopogon sp.), lemon (Corymbia citriodora) and andiroba oils Not applicable Not applicable Not applicable · vs Not applicable |
The authors name citronella among the most studied essential oils. They say robust toxicity data and information on effects on non-target organisms are lacking, the exact mode of action is mostly theory, and essential oils act for a shorter time because they evaporate quickly from the skin, so they need special repellent vehicles such as encapsulation. DEET is the reference standard but has considerable toxicity concerns and is not recommended for children up to 6 months old and pregnant women, according to the review. Explains why plant-oil repellents often wear off sooner than synthetic ones. Methods, limits and fundingOutcomes: Safety, mechanism, efficacy and product-development problems Limitations: Narrative review; no pooled numbers for citronella. The DEET statements are the authors' and were not checked against a regulator here. Funding and conflicts: The authors declare no competing interests. Read: abstract |
| Asadollahi 2019 Effectiveness of plant-based repellents against different Anopheles species: a systematic review. Malaria Journal · PMID 31864359 · DOI |
Systematic review |
62 62 trials (search to July 2018) of plant extracts and oils against Anopheles mosquitoes |
Plant extracts and essential oils including citronella oil Not applicable Not applicable Not applicable · vs Not applicable |
The highest repellency came from a Ligusticum sinense extract, followed by citronella, pine, Dalbergia sissoo, peppermint and Rhizophora mucronata oils, with complete protection times ranging from 9.1 to 11.5 hours. Many other oils also showed good repellency, with 8 hours of complete repellency. The authors say plant oils could be formulated into eco-friendly repellents and may be suitable alternatives to synthetic repellents in future. Citronella was among the top plant repellents in the pooled set of trials, within a protection range of 9.1 to 11.5 hours for the group. Methods, limits and fundingOutcomes: Percentage repellency and protection time Limitations: The 9.1 to 11.5 hour range covers the whole group of top products, not citronella alone. The abstract does not say how many trials were done in people versus in the laboratory or on animals, or how the products were made. These results differ a lot from the shorter times in the 2026 human-study review and the 2002 test. Funding and conflicts: The authors declare no competing interests. Read: abstract |
| Boots 2008 Fire-eater's lung. Anaesthesia and Intensive Care · PMID 18564809 · DOI |
Case report |
2 Two fire-eaters with lung injury from breathing in liquid fuel |
Fire-eating fuel, including one reported case of citronella oil Not applicable Not applicable Not applicable · vs Not applicable |
The authors report that aspiration of a hydrocarbon from fire-eating can cause severe necrotising pneumonia with cysts and large pleural effusions, though there is usually little lasting lung injury. They describe two cases, one of which is the first reported case of citronella oil aspiration. Shows that breathing citronella oil into the lungs, as can happen with fire-eating, can injure them. Methods, limits and fundingOutcomes: Lung injury after aspiration Limitations: Two cases only; the abstract does not describe what the product was beyond calling it citronella oil, so it may be a fuel product rather than the pure essential oil. Funding and conflicts: Not stated in the abstract. Read: abstract |
| CDC 2024 Preventing Mosquito Bites (US Centers for Disease Control and Prevention) cdc.gov · Source |
Authoritative guidance |
Not applicable | Mosquito repellents Not applicable Not applicable Not applicable · vs Not applicable |
NOT VERIFIED. The CDC page returned an access-denied error when we tried to open it. Our earlier summary says the CDC recommends EPA-registered repellents and does not know how effective non-registered natural repellents are; the EPA page we did read confirms only that the CDC recommends EPA-registered products. Not used for any claim beyond what the EPA page states. Methods, limits and fundingOutcomes: Which repellents the CDC recommends Limitations: Page not opened. Funding and conflicts: Not applicable. Read: summary-only |
| EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP); Bampidis 2024 Safety and efficacy of a feed additive consisting of an essential oil derived from the leaves of Cymbopogon nardus (L.) Rendle (citronella oil) for use in all animal species (FEFANA asbl). EFSA Journal · PMID 38784838 · DOI |
Regulatory scientific opinion |
Animal species (as a feed flavouring); the opinion also covers consumers, users and the environment | Citronella oil from the leaves of Cymbopogon nardus Leaf Not applicable Not applicable · vs Not applicable |
EFSA concluded the oil is of low concern for long-living and reproductive animals at the stated feed levels, with the lowest level for cats (2.0 mg/kg complete feed) and a higher one for dogs (10 mg/kg). It is expected to be of no concern for consumers and the environment at those levels. The oil should be considered an irritant to skin and eyes and a dermal sensitiser. When handling the oil, unprotected users may be exposed to methyleugenol, so exposure should be minimised. Regulator treats the oil as a skin and eye irritant and skin sensitiser; handlers should limit exposure to methyleugenol. Methods, limits and fundingOutcomes: Safety of the oil for animals, consumers, users and the environment Limitations: About animal feed flavouring, not repellent or skin products. The animal feed levels are not human amounts and must not be read as such. We read the abstract only. Funding and conflicts: Regulatory body; conflict-of-interest declarations are held by EFSA. Read: abstract |
| Faridah 2026 Effectiveness of mosquito repellents for human: A systematic review of human-based studies. Acta Tropica · PMID 42285396 · DOI |
Systematic review |
19 Human studies from 2015 to 2025 of mosquito repellents (skin products, wearables, spatial products, treated clothing); 19 of 1287 records met the criteria |
Mosquito repellents (DEET-based, essential-oil-based including citronella, and others) Not applicable Not applicable Not applicable · vs Not applicable |
DEET-based lotions or ointments gave the longest complete protection, often five to nine hours, with no reported skin reactions. Natural repellents based on essential oils such as citronella, lemon eucalyptus, neem and lemongrass usually gave shorter protection, commonly two to four hours. Microencapsulation and nanoemulsions improved some formulations. The authors say synthetic topical repellents remain the most reliable option for long protection and plant-based products may suit short-term or add-on use. Citronella-type products: usually about two to four hours of complete protection; DEET: often five to nine hours. Methods, limits and fundingOutcomes: Complete protection time, repellency rate, safety Limitations: Results were summarised in words, not pooled, because the studies were too different. Citronella is grouped with other plant oils, so the abstract gives no figure for citronella alone. An erratum to this paper exists (Acta Trop 2026;280:108206); we did not read it. Funding and conflicts: The authors declare no competing interests. Read: abstract |
| Fradin 2002 Comparative efficacy of insect repellents against mosquito bites. New England Journal of Medicine · PMID 12097535 · DOI |
Controlled laboratory test |
15 15 volunteers tested in a controlled laboratory with mosquitoes of fixed species, age and hunger |
Seven botanical repellents, four DEET products, one IR3535 product, wristbands and a moisturizer Not applicable Not applicable Not applicable · vs Not applicable |
A 23.8 percent DEET product had a mean complete-protection time of 301.5 minutes. A soybean-oil-based repellent protected for an average of 94.6 minutes. The IR3535 product protected for 22.9 minutes. All other botanical repellents gave a mean protection of under 20 minutes. Repellent-impregnated wristbands gave no protection. The authors concluded non-DEET repellents then available could not be relied on for prolonged protection where mosquito-borne disease is a real threat. Botanical repellents tested: mean protection under 20 minutes (except the soybean-oil product). Methods, limits and fundingOutcomes: Mean complete-protection time (minutes) Limitations: The abstract does not name which botanical products were tested, so we cannot say which contained citronella. Products sold in 2002 may differ from today's. Small test, one laboratory setting. Funding and conflicts: Not stated in the abstract. Read: abstract |
| GBIF Secretariat 2026 Cymbopogon nardus (L.) Rendle (GBIF backbone taxonomy) api.gbif.org · Source |
Taxonomy database plant |
Not applicable | Cymbopogon nardus Whole plant Not applicable Not applicable · vs Not applicable |
API match returned Cymbopogon nardus (L.) Rendle, status ACCEPTED, exact match, family Poaceae, usage key 2705267 (checked 2026-10-25). Name is accepted. Methods, limits and fundingOutcomes: Accepted name Limitations: Database record only. Funding and conflicts: Not applicable. Read: api-record |
| GBIF Secretariat 2026 Cymbopogon winterianus Jowitt ex Bor (GBIF backbone taxonomy) api.gbif.org · Source |
Taxonomy database plant |
Not applicable | Cymbopogon winterianus Whole plant Not applicable Not applicable · vs Not applicable |
API match returned Cymbopogon winterianus Jowitt ex Bor, status ACCEPTED, exact match, family Poaceae, usage key 2705273 (checked 2026-10-25). Name is accepted. Methods, limits and fundingOutcomes: Accepted name Limitations: Database record only. Funding and conflicts: Not applicable. Read: api-record |
| Lalko 2006 Investigation of the dermal sensitization potential of various essential oils in the local lymph node assay. Food and Chemical Toxicology · PMID 16324777 · DOI |
Animal test mouse |
Mice (local lymph node assay) given seven essential oils and three single compounds on the skin | Basil, citronella, clove leaf, geranium, litsea cubeba, lemongrass and palmarosa oils; citral, eugenol, geraniol Not applicable Not applicable Not applicable · vs Not applicable |
Citronella and geranium oils gave negative results. Basil oil was classed moderate or stronger; clove leaf, litsea cubeba, lemongrass and palmarosa oils were weak. The single compounds citral, eugenol and geraniol were positive. In this mouse test citronella oil did not cause a positive sensitisation response. Methods, limits and fundingOutcomes: Stimulation index and the concentration needed for a positive reaction (EC3) Limitations: Mouse test, not people. It does not match the human patch-test finding, so the two should be read together, not one without the other. The authors work at the Research Institute for Fragrance Materials, a fragrance-industry body. Funding and conflicts: Authors are from the Research Institute for Fragrance Materials (industry-linked). Funding not stated in the abstract. Read: abstract |
| Lindsay 1996 Evaluation of the efficacy of 3% citronella candles and 5% citronella incense for protection against field populations of Aedes mosquitoes. Journal of the American Mosquito Control Association · PMID 8827606 |
Field trial |
8 Eight subjects in a woodlot in Guelph, Ontario, Canada, 26 July to 10 August 1995, with 5-minute biting counts |
3 percent citronella candles and 5 percent citronella incense Not applicable Not applicable Not applicable · vs Not applicable |
On average subjects received 6.2, 8.2, 8.2 and 10.8 bites per 5 minutes at positions with citronella candles, citronella incense, plain candles and no candles. Significantly fewer bites were received with citronella candles and incense than at untreated positions, but the overall reduction was only 42.3 and 24.2 percent. Citronella candles cut bites by about 42 percent and incense by about 24 percent in this woodlot. Methods, limits and fundingOutcomes: Bites per 5 minutes Limitations: Eight people, one site, one season, 1995. Funding and conflicts: Not stated in the abstract. Read: abstract |
| Müller 2008 Ability of essential oil candles to repel biting insects in high and low biting pressure environments. Journal of the American Mosquito Control Association · PMID 18437832 · DOI |
Controlled field experiment |
Outdoor tests with candles and traps, then with volunteers in high and low biting-pressure sites | Citronella, linalool and geraniol candles (5 percent) Not applicable Not applicable Not applicable · vs Not applicable |
At 1.0 m, citronella candles reduced female mosquitoes caught in traps by 35.4 percent and sand flies by 15.4 percent. Linalool candles reduced mosquitoes by 64.9 percent and geraniol candles by 81.5 percent. Repellency dropped significantly at 2 m and 3 m. The volunteer part tested the best candle, geraniol, not citronella. Citronella candle: about one third fewer mosquitoes caught at 1 m; much less at greater distance. Methods, limits and fundingOutcomes: Mosquitoes and sand flies caught; biting pressure on volunteers Limitations: Trap catches for citronella; the volunteer test did not use citronella. Funding and conflicts: Not stated in the abstract. Read: abstract |
| Müller 2009 Efficacy of the botanical repellents geraniol, linalool, and citronella against mosquitoes. Journal of Vector Ecology · PMID 20836800 · DOI |
Controlled field experiment |
Mosquitoes caught in traps near commercially available candles or diffusers, indoors and outdoors | Citronella, linalool and geraniol candles (88 g, 5 percent active) and diffusers (20 g, 100 percent active) Not applicable Not applicable Not applicable · vs Not applicable |
All three substances repelled more mosquitoes than the unprotected control. Indoors, citronella candles repelled only 14 percent and citronella diffusers 68 percent. Geraniol candles repelled 50 percent and geraniol diffusers 97 percent; linalool diffusers 93 percent. Outdoors, citronella diffusers placed 6 m from the traps repelled 22 percent of female mosquitoes, linalool 58 percent and geraniol 75 percent. The authors concluded geraniol was significantly more active than citronella or linalool in both settings. Citronella was the weakest of the three; diffusers worked better than candles. Methods, limits and fundingOutcomes: Repellency rate (fewer mosquitoes caught) Limitations: Trap catches, not bites on people. Commercial products, so exact composition is not known from the abstract. Funding and conflicts: Not stated in the abstract. Read: abstract |
| NCCIH 2020 Aromatherapy (National Center for Complementary and Integrative Health) nccih.nih.gov · Source |
Authoritative guidance |
Not applicable | Aromatherapy in general Not applicable Not applicable Not applicable · vs Not applicable |
NOT RE-OPENED in this build. Our earlier summary, which recorded it as read, found no support for citronella as aromatherapy. The statement on this page is only that we found no human trial of citronella scent for mood, sleep or pain. Used only for the statement that we found no such trial. Methods, limits and fundingOutcomes: Evidence for aromatherapy Limitations: Summary-only; not re-opened. Funding and conflicts: Not applicable. Read: summary-only |
| National Pesticide Information Center 2026 Oil of Citronella Fact Sheet (National Pesticide Information Center, Oregon State University) npic.orst.edu · Source |
Authoritative guidance |
Not applicable | Oil of citronella Leaf (distilled from two grass varieties) Not applicable Not applicable · vs Not applicable |
Page read in full. Oil of citronella is distilled from two grass varieties, is yellow to brown with a grassy or floral smell, and its main components are citronellol, citronellal and geraniol; composition varies by grass variety. First registered in the US in 1948; on EPA's minimum-risk pesticides list; found in over a dozen registered pesticide products (sprays, lotions, candles, pellets, pouches, sunscreens, wristbands, flea collars). It repels rather than kills, by masking scents that attract insects. It is also used as a food flavouring and is Generally Recognized as Safe by the FDA as a food additive, according to NPIC. It can be mildly irritating to skin and eyes and may cause skin allergies with prolonged or frequent exposure; if eaten, people may cough or have throat irritation. Its cancer potential has not been studied. Methyleugenol, a minor component, is reasonably anticipated to be a human carcinogen by the US Department of Health and Human Services (caused tumours in mice). Some products should not be used on children under six months unless directed by a doctor. Practically non-toxic to birds, slightly toxic to fish. Plain US pesticide-information summary: mild irritant, can cause skin allergy, contains minor methyleugenol, labels restrict use in young babies. Methods, limits and fundingOutcomes: What it is, how it works, exposure, safety, children, environment Limitations: A summary page; it cites the underlying studies but we did not re-open them. The year shown is the year we read it; the page's own revision date was not captured. Funding and conflicts: Not applicable. Read: full-text |
| Pet Poison Helpline Essential Oils (Pet Poison Helpline) petpoisonhelpline.com · Source |
Authoritative guidance |
Not applicable | Essential oils in general Not applicable Not applicable Not applicable · vs Not applicable |
Page read in full. Essential oil poisoning can affect all species, but cats and birds are at the greatest risk. Common signs are drooling, vomiting, tiredness, loss of appetite and irritation of the skin, airways and mouth; severe signs can develop with some oils. Signs usually start within 6 to 8 hours. Swallowing is the highest-risk route, then skin, then breathing. The page's list of oils that commonly cause poisoning does not name citronella. Owners should keep the product label and concentration; do not make an animal vomit; call a veterinarian or the helpline. Pet-poison service: essential oils can poison all pets, cats and birds most; its list of common culprits does not name citronella. Methods, limits and fundingOutcomes: Essential oil poisoning in pets Limitations: General page; no citronella-specific statement, so it neither proves nor disproves safety for pets. Funding and conflicts: Not applicable. Read: full-text |
| Poison Control Essential oils: Poisonous when misused (Poison Control, America's Poison Centers) poison.org · Source |
Authoritative guidance |
Not applicable | Essential oils in general Not applicable Not applicable Not applicable · vs Not applicable |
Page read in full. Misuse of essential oils can cause serious poisoning. Many can cause rashes on the skin and some can be poisonous if absorbed through the skin or swallowed. Aspirating an essential oil (choking so some enters the lungs) can cause pneumonia. Children have thin skin and immature livers, which might make them more susceptible. Essential oils may interact with medicines. Pure essential oils are potent; diluting them in a carrier oil is the best way to avoid a bad reaction, and they should not be used on damaged skin. Stop using at once if a rash occurs and wash it off. Keep bottles locked up out of the sight and reach of children and pets, or discard them if you have young children. It can be hard to know exactly what is in a bottle: species, concentration or contaminants. Worked examples of child poisoning on the page involve camphor and lavender, not citronella. If someone swallows an essential oil, call 1-800-222-1222 (US) or use the online tool. Poison-centre advice for all essential oils: do not swallow, dilute for skin, lock away from children and pets. Methods, limits and fundingOutcomes: Poisoning risks, skin use, allergy, children, medicines Limitations: General essential-oil page; it does not discuss citronella oil. The page carries no publication date. Funding and conflicts: Not applicable. Read: full-text |
| Rehman 2014 Plant based products: use and development as repellents against mosquitoes: A review. Fitoterapia · PMID 24631763 · DOI |
Narrative review |
Review of plant-based mosquito repellents and how they are tested | Plant essential oils and traditional plants (Eucalyptus, Ocimum and Cymbopogon most cited) Not applicable Not applicable Not applicable · vs Not applicable |
The review names Eucalyptus, Ocimum and Cymbopogon species as the most cited promising plants. It says results are hard to compare because test systems and standards differ, forearm tests were done with different treated areas, and results have not been tested for how long they last in field conditions. Protection time can be raised with a helper such as vanillin and with formulation methods like microencapsulation and nanoemulsion. Cymbopogon is among the most studied genera, but results are hard to compare between studies. Methods, limits and fundingOutcomes: Repellency, testing methods Limitations: Narrative review; no figure for citronella alone; 2014. Funding and conflicts: Not stated in the abstract. Read: abstract |
| Sheikh 2013 Characterizing risk factors for pediatric lamp oil product exposures. Clinical Toxicology · PMID 24066734 · DOI |
Poison centre data and parent survey |
39 US poison-centre calls about lamp oil exposure 2000 to 2010, plus a telephone survey of parents of 39 children who swallowed lamp oil products |
Lamp oil products (the survey mostly involved tiki torch fuel) Not applicable Not applicable Not applicable · vs Not applicable |
Lamp oil poisonings continue to occur in children despite restricted sale of coloured and scented lamp oils. Most exposures were in children around 2 years old, at home, with the product on a table or shelf; the survey ones mostly involved tiki torch fuel. About half had no symptoms; cough was the most common complaint among those who did. The authors suggest safe storage and parent awareness. Torch and lamp fuels are a real swallowing hazard for toddlers, which is why they must be kept apart from essential oils and out of reach. Methods, limits and fundingOutcomes: Who is exposed, where, and what symptoms Limitations: The abstract does not say that any of these products were citronella-scented or contained citronella oil. It is included as the closest child-poisoning evidence for lamp and torch products, not as evidence about citronella oil. Funding and conflicts: Authors report no declarations of interest; the views are not official CDC positions. Read: abstract |
| US Environmental Protection Agency 2026 Skin-Applied Repellent Ingredients (US Environmental Protection Agency) epa.gov · Source |
Regulatory guidance |
Not applicable | Oil of citronella and other repellent ingredients Not applicable Not applicable Not applicable · vs Not applicable |
Page read in full (last updated 23 January 2026). Oil of citronella is listed as an active ingredient in EPA-registered skin-applied insect repellents: three registered products, and it is also used in unregistered products that meet the requirements for exemption from registration. For comparison the page lists DEET (more than 500 products), picaridin (about 40), IR3535 (about 45), oil of lemon eucalyptus and p-menthane-3,8-diol (6 each) and catnip oil (4). EPA lists oil of citronella among approved skin-repellent ingredients, with far fewer registered products than DEET. Methods, limits and fundingOutcomes: Which ingredients are in EPA-registered skin repellents Limitations: A list of ingredients and product counts. It does not state how long any product protects. Funding and conflicts: Not applicable. Read: full-text |
| US Environmental Protection Agency 2026 Using Insect Repellents Safely and Effectively (US Environmental Protection Agency) epa.gov · Source |
Regulatory guidance |
Not applicable | Insect repellents in general Not applicable Not applicable Not applicable · vs Not applicable |
Page read in full. Read and follow the label; apply only to exposed skin; never over cuts, wounds or irritated skin; do not spray into the face or in enclosed spaces; do not use any product on pets or other animals unless the label says it is for animals; store out of the reach of children. For children, apply to your own hands first and do not let children handle the product or put it on their hands. An EPA registration number means the company gave EPA technical information on the effectiveness of the product, and the CDC recommends products registered by EPA. Effectiveness varies with sweating, water, temperature and the person. EPA advice: choose a product with an EPA registration number, follow the label, keep it off pets and children's hands. Methods, limits and fundingOutcomes: Safe use of repellents, children, effectiveness Limitations: General repellent advice, not citronella-specific. Funding and conflicts: Not applicable. Read: full-text |
| de Groot 2016 Essential Oils, Part IV: Contact Allergy. Dermatitis · PMID 27427818 · DOI |
Narrative review |
Review of essential oils reported to cause contact allergy; patch tests in consecutive patients suspected of contact dermatitis | Nearly 80 essential oils, including citronella Not applicable Not applicable Not applicable · vs Not applicable |
Nearly 80 essential oils have caused contact allergy. Fifty-five were tested in consecutive patients suspected of contact dermatitis, and nine showed more than 2 percent positive patch-test reactions: laurel, turpentine, orange, tea tree, citronella, ylang-ylang, sandalwood, clove and costus root. Relevance data are generally missing or inadequate. Most reactions come from applying pure oils or high-concentration products. Reactions across several essential oils and with fragrance mix are frequent. Citronella oil is among nine oils with more than 2 percent positive patch tests in people who were already suspected of skin allergy. Methods, limits and fundingOutcomes: Contact allergy and patch-test reactions Limitations: The patients were already suspected of contact dermatitis, so this does not tell us how often allergy happens in the general public. The abstract gives no citronella-specific percentage. Funding and conflicts: Not stated in the abstract. Read: abstract |
What we do not know yet
- No citronella-only protection time from the human-study review.
- No trial of citronella in children, pregnancy or older people.
- No information on pregnancy, breastfeeding, asthma, seizures or medicines specific to citronella.
- No safe skin percentage found.
- The CDC and NCCIH pages were not read.
How new research is added
New studies are found by a saved PubMed search and placed in a review queue. A person reads each one before it changes any rating or safety wording.
Lab markers
What changed in blood or saliva tests during trials. A changed number is not the same as feeling or being healthier, and we give no "normal ranges".
Other 3
Complete protection time
Lengthened in trials
How long a repellent keeps all bites away before the first bite or landing.
Low certaintyResults and what it means
Why it was measured
The main way repellents are compared.
Statistical vs. clinical meaning
The three sources give very different times, which shows how much the result depends on product and test.
Safety implication
A short protection time means reapplying or switching products matters where disease risk is real.
| Study | Result | People | Product |
|---|---|---|---|
| 6 | Natural oil repellents such as citronella usually two to four hours; DEET products often five to nine hours. | 19 human studies, 2015 to 2025 | Skin repellents of different types |
| 7 | Botanical repellents other than a soybean-oil product protected under 20 minutes on average; 23.8 percent DEET 301.5 minutes. | 15 volunteers, laboratory | Seven botanical repellents and several others |
| 2 | Top plant products including citronella oil: 9.1 to 11.5 hours across the group. | 62 trials, study types not stated | Plant extracts and oils |
Bites received or mosquitoes caught
Lowered in trials
Counting actual bites or landings, or trapped insects, near a product.
Low certaintyResults and what it means
Why it was measured
Used for candles and area products, where protection time is not measured.
Statistical vs. clinical meaning
Fewer bites, but far from complete protection.
Safety implication
None reported.
| Study | Result | People | Product |
|---|---|---|---|
| 11 | 42.3 percent fewer bites with 3 percent citronella candles and 24.2 percent fewer with 5 percent citronella incense. | 8 subjects, woodlot | Citronella candles and incense |
Mosquitoes caught in traps near a product
Lowered in trials
The fewer mosquitoes caught near a candle or diffuser compared with none, the more it repels.
Low certaintyResults and what it means
Why it was measured
A way to test area products without people being bitten.
Statistical vs. clinical meaning
Effects fall quickly with distance.
Safety implication
None reported.
| Study | Result | People | Product |
|---|---|---|---|
| 12 | Citronella candle, 1 m: 35.4 percent fewer female mosquitoes and 15.4 percent fewer sand flies; less at 2 m and 3 m. | Outdoor trap experiment | 5 percent citronella candle |
| 13 | Indoors, citronella candles 14 percent and diffusers 68 percent repellency; outdoors diffusers at 6 m 22 percent. | Indoor and outdoor trap experiments | Citronella candles and diffusers |
Safety
What studies and official sources say about side effects, medicines and who should check first. Each point shows what kind of evidence it comes from.
Main points to know 5
- Do not swallow it; keep it away from children. Poison Control warns that essential oils can cause serious poisoning, that some are poisonous if swallowed, and that an oil breathed into the lungs while choking can cause pneumonia. Children have thin skin and immature livers and may be more vulnerable. NPIC says that if citronella oil is eaten, people may cough or have throat irritation. A case report describes lung injury after citronella oil was breathed into the lungs in a fire-eater. We found no case series of citronella oil poisoning in children, and no safe amount to swallow is given anywhere. If anyone has swallowed it, call a poison centre or emergency services (US Poison Help: 1-800-222-1222; numbers elsewhere were not checked). Authoritative guidance 17 15 3
- Do not mix it up with lamp or torch fuel. Swallowed lamp and torch fuel is a known danger to toddlers: a US study of poison-centre calls and a parent survey found most cases in children around two years old, at home, with the product on a table or shelf. Cough was the most common symptom. The abstract does not say whether any of these fuels were citronella-scented, so this is evidence about fuels, not about the essential oil. Keep essential oils, repellents and fuels in separate, clearly marked places, locked away from children. Poison centre data 19 17
- Skin irritation and allergy are real. EFSA says to treat the oil as an irritant to skin and eyes and as a skin sensitiser. NPIC says it can be mildly irritating and may cause skin allergy with prolonged or frequent exposure. A review of patch tests found citronella among nine oils with more than 2 percent positive reactions in people already suspected of contact dermatitis, with most reactions from pure oils or high-concentration products. A mouse test paid for by a fragrance-industry institute was negative. The evidence is mixed, so treat it as a possible allergen. Mixed 5 15 22 10
- Pure oil is strong; never use it undiluted. Poison Control says pure essential oils are potent, that diluting in a carrier oil is the best way to avoid a bad reaction, and that they should not be used on damaged skin. Stop at once if a rash appears and wash the oil off. No safe skin percentage for citronella oil was found in the sources we read, so none is given. Authoritative guidance 17 21
- Pets, especially cats. Pet Poison Helpline says essential oil poisoning can affect all species and that cats and birds are at greatest risk; the signs include drooling, vomiting and tiredness. Its list of common culprits does not name citronella, so this is a general warning, not a citronella finding. The EPA says not to use any repellent on pets unless the label says it is for animals. EFSA set the lowest safe feed level for cats of the animals it named. Ask a vet before using any citronella product around pets. Authoritative guidance 16 21 5
Side effects 5
| Effect | How often | Severity and recovery | Evidence |
|---|---|---|---|
| Skin irritation, redness, rash Rash is the most common reaction to essential oils, according to Poison Control. | Not known | mild to moderate Usually settles when stopped (not stated in sources) | Authoritative guidance 15 5 17 |
| Allergic contact dermatitis Human patch tests and a mouse test disagree. | More than 2 percent positive patch tests in people suspected of contact dermatitis (review); not a rate for the public | mild to moderate Not stated | Review 22 10 |
| Eye irritation Avoid eyes and mouth; the EPA says do not apply near eyes and mouth. | Not known | mild Not stated | Regulatory 5 15 |
| Cough or throat irritation if swallowed Aspiration can cause pneumonia. | Not known | mild to serious Not stated | Authoritative guidance 15 17 |
| Lung injury after breathing the oil in A fire-eater case; not everyday use. | One reported case | severe The report says there is usually little lasting injury with fire-eater's lung in general | Case report 3 |
Medicines and supplements 3
| With | Why it matters | Importance | Evidence | What to do |
|---|---|---|---|---|
| Medicines in general prescription | Poison Control says essential oils may interact with medicines; no citronella-specific mechanism is given. | No documented citronella-medicine interaction was found. | Authoritative guidance Not enough evidence 17 | Ask a pharmacist if you take regular medicines, especially for swallowed products. |
| Other fragrance products and essential oils (skin allergy) other | The review notes frequent reactions across several essential oils and with fragrance mix. | Someone allergic to one may react to others. | Review Low certainty 22 | If you have had a fragrance allergy, ask a skin doctor before use. |
| Herbs and supplements herb | None described. | No source read describes any. | None Not enough evidence | Not applicable. |
Who should check first 5
| Situation | Advice | Evidence |
|---|---|---|
| Swallowing, for anyone | Do not swallow the oil. Poison centres advise calling for help if it is swallowed. | Authoritative guidance 17 15 |
| Babies under six months | NPIC says some oil of citronella products should not be used on children under six months unless a doctor directs it; this is on their labels. | Authoritative guidance 15 |
| Damaged or irritated skin | Do not apply to broken, cut or irritated skin. | Authoritative guidance 17 21 |
| Known fragrance or essential oil allergy | Avoid, or ask a skin doctor. | Review 22 |
| Pregnancy and breastfeeding | We found no citronella-specific source on pregnancy or breastfeeding. That is not proof of safety. Ask a doctor, midwife or pharmacist before use. | None |
Overdose, product quality and regulators
Summary. Citronella oil is a skin and eye irritant and possible skin sensitiser, mildly irritating according to NPIC. Swallowing or breathing it into the lungs is a poisoning risk. No amount that is safe to swallow is given in any source we read.
Animal. EFSA judged the oil of low concern in animal feed at stated levels, with the lowest level for cats. That is a feed-flavouring assessment, not advice for pets or people. NPIC says it is practically non-toxic to birds and slightly toxic to fish.
Human doses studied. Not applicable. This page gives no amounts.
High dose or long term signals. NPIC says methyleugenol, a minor component of the oil, is reasonably anticipated to be a human carcinogen by the US Department of Health and Human Services (it caused tumours in mice), and that the cancer potential of citronella oil itself has not been studied. EFSA says handlers should keep exposure to methyleugenol as low as possible.
Overdose response. Call a poison centre or emergency services at once. For a pet, call a vet or an animal poison line.
Genotoxicity. NPIC says studies showed the oil does not alter or damage genes (not re-read).
Oils are not equal. Poison Control says it can be hard to know the species, concentration or contaminants in a bottle. NPIC says the make-up varies by grass variety.
Two grass varieties and varying make-up. The oil is distilled from two grasses; main components are citronellol, citronellal and geraniol, in amounts that vary. 15
Registered and unregistered products. The EPA lists oil of citronella as an active ingredient in three registered skin repellents and says it is also used in unregistered products that meet exemption rules. We found no information on how well the unregistered ones work. 20
Product make-up affects results. A review says better, more even oils and special product designs are needed because the oil evaporates fast. 1
| Body | Action | Date |
|---|---|---|
| US Environmental Protection Agency (United States) | Lists oil of citronella as an active ingredient in EPA-registered skin-applied insect repellents (three registered products) and also in unregistered products meeting exemption requirements. EPA says a registration number means the company gave effectiveness information, and the CDC recommends EPA-registered products. source | 2026-01-23 |
| European Food Safety Authority (FEEDAP Panel) (European Union) | Opinion on citronella oil from Cymbopogon nardus as an animal feed flavouring: low concern at stated feed levels; treat the oil as an irritant to skin and eyes and a dermal sensitiser; limit handlers' exposure to methyleugenol. source | 2024-05-23 |
When to get medical help
- Anyone who may have swallowed citronella oil, a repellent or lamp or torch fuel: call a poison centre or emergency services now (US Poison Help 1-800-222-1222), even if they seem well.
- Coughing, choking, wheezing or trouble breathing after swallowing or breathing in the oil.
- Swelling of the face or lips, hives or trouble breathing after skin contact: treat as an emergency.
- A spreading, blistering or painful rash: stop use, wash off the oil and see a doctor.
- A pet that drools, vomits or is weak after contact: call a vet or an animal poison line.
Stop using the product and contact a clinician or emergency service. In the US, Poison Control is 1-800-222-1222.
General information only, not medical advice. Ask a clinician or pharmacist before use, especially with medicines, in pregnancy or with a health condition. See the Natural Remedy Safety guide.
Frequently asked questions
Is citronella oil safe?
Does citronella oil keep mosquitoes away?
Is citronella as good as DEET?
What does the EPA say about citronella?
Do citronella candles work?
Can citronella oil cause an allergy?
What if a child swallows it?
Is citronella oil safe for dogs and cats?
Is it safe in pregnancy or for babies?
We found no citronella-specific advice for pregnancy. NPIC says some products should not be used on children under six months unless a doctor directs it. Ask a doctor, midwife or pharmacist.
Does citronella prevent malaria or dengue?
Is citronella the same as lemongrass?
No. They are close relatives, and EFSA assessed the two oils separately.
Does it help with mood, sleep or pain?
We found no human trial.
Explore by health goal
Editorial transparency
- Written by
- AlternativeMed editorial team. Research compiled with AI assistance, then checked against PubMed records.
- Medical review
- None. This page has not been reviewed by a physician or pharmacist.
- First published
- 2026-10-25
- Last substantive update
- 2026-10-25
- How we research
- We started from our existing citronella summary, then read the abstract of every PubMed study cited and the EPA, NPIC, Poison Control and Pet Poison Helpline pages. The CDC page could not be opened and the NCCIH page was not re-opened; where that matters the page says so.
- How we rate evidence
- See "How we rate evidence" in the Evidence tab.
- Independence
- No product is promoted on this page. No affiliate links are shown.
Sources 22
Each source was opened and checked. Where we read only the abstract, it says so. The small numbers in the text point here.
- Almeida AR, Oliveira ND, Pinheiro FASD, et al.. Challenges encountered by natural repellents: Since obtaining until the final product.. Pesticide Biochemistry and Physiology. 2023. PMID 37666610. DOI 10.1016/j.pestbp.2023.105538. (abstract)
- Asadollahi A, Khoobdel M, Zahraei-Ramazani A, et al.. Effectiveness of plant-based repellents against different Anopheles species: a systematic review.. Malaria Journal. 2019. PMID 31864359. DOI 10.1186/s12936-019-3064-8. (abstract)
- Boots RJ, Weedon ZJ. Fire-eater's lung.. Anaesthesia and Intensive Care. 2008. PMID 18564809. DOI 10.1177/0310057X0803600318. (abstract)
- CDC. Preventing Mosquito Bites (US Centers for Disease Control and Prevention). cdc.gov. 2024. (summary-only)
- EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP); Bampidis V, et al.. Safety and efficacy of a feed additive consisting of an essential oil derived from the leaves of Cymbopogon nardus (L.) Rendle (citronella oil) for use in all animal species (FEFANA asbl).. EFSA Journal. 2024. PMID 38784838. DOI 10.2903/j.efsa.2024.8790. (abstract)
- Faridah L, Nurhakim RA, Astuti RRUNW, et al.. Effectiveness of mosquito repellents for human: A systematic review of human-based studies.. Acta Tropica. 2026. PMID 42285396. DOI 10.1016/j.actatropica.2026.108182. (abstract)
- Fradin MS, Day JF. Comparative efficacy of insect repellents against mosquito bites.. New England Journal of Medicine. 2002. PMID 12097535. DOI 10.1056/NEJMoa011699. (abstract)
- GBIF Secretariat. Cymbopogon nardus (L.) Rendle (GBIF backbone taxonomy). api.gbif.org. 2026. (api-record)
- GBIF Secretariat. Cymbopogon winterianus Jowitt ex Bor (GBIF backbone taxonomy). api.gbif.org. 2026. (api-record)
- Lalko J, Api AM. Investigation of the dermal sensitization potential of various essential oils in the local lymph node assay.. Food and Chemical Toxicology. 2006. PMID 16324777. DOI 10.1016/j.fct.2005.10.006. (abstract)
- Lindsay LR, Surgeoner GA, Heal JD, Gallivan GJ. Evaluation of the efficacy of 3% citronella candles and 5% citronella incense for protection against field populations of Aedes mosquitoes.. Journal of the American Mosquito Control Association. 1996. PMID 8827606. (abstract)
- Müller GC, Junnila A, Kravchenko VD, et al.. Ability of essential oil candles to repel biting insects in high and low biting pressure environments.. Journal of the American Mosquito Control Association. 2008. PMID 18437832. DOI 10.2987/8756-971X(2008)24[154:AOEOCT]2.0.CO;2. (abstract)
- Müller GC, Junnila A, Butler J, et al.. Efficacy of the botanical repellents geraniol, linalool, and citronella against mosquitoes.. Journal of Vector Ecology. 2009. PMID 20836800. DOI 10.1111/j.1948-7134.2009.00002.x. (abstract)
- NCCIH, National Institutes of Health. Aromatherapy (National Center for Complementary and Integrative Health). nccih.nih.gov. 2020. (summary-only)
- National Pesticide Information Center. Oil of Citronella Fact Sheet (National Pesticide Information Center, Oregon State University). npic.orst.edu. 2026. (full-text)
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