Essential Oils & Aromatherapy · Essential oil (caution)
Tagetes (Marigold) Oil
Tagetes minuta L. and Tagetes patula L. · also called Tagetes oil, marigold oil, wild marigold oil, French marigold oil
Tagetes oil is a strong-smelling essential oil from marigold-type plants of the genus Tagetes. It is mostly a perfumery and pest-control material, and it is not the same as calendula. We found no human trial for any health use: the research is test-dish, animal and farm work. The main caution: the EU safety committee limits it in cosmetics because it can make skin react to sunlight, and it should never be swallowed.
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 Tagetes (Marigold) Oil
Tagetes oil is a strong perfumery and pest-control oil from marigold-type plants. Safety comes first: the EU safety committee limits it in cosmetics because it can make skin react to sunlight and bars it from sunscreens, marigold chemicals cause skin allergy, and it should not be swallowed. We found no human trial of any health use. The research is test-dish, mouse, tick and cattle work.
What tagetes oil is
Tagetes is a group of marigolds in the daisy family (Asteraceae), native to America. The oils discussed here come from Tagetes minuta (wild marigold) and Tagetes patula (French marigold). GBIF lists T. minuta as accepted and T. patula as a synonym of T. erecta, while the EU opinion names T. minuta and T. patula separately.
It is not calendula. Calendula (pot marigold) is a different plant, and marigold flower extracts sold for lutein are another product.
The oil is a mixture. Papers name tagetone, dihydrotagetone, ocimenones, tagetenones, beta-ocimene and beta-pinene among its compounds. The thiophenes that drive the sun and allergy warnings were richest in the roots in an Italian study.
What people use it for, and how strong the evidence is
Mostly perfumery and pest control. The EU opinion exists because the oil is a fragrance ingredient. In test dishes, tagetes oils slowed bacteria and biofilm and showed antioxidant activity. A lab study on dairy surfaces used a special capsule form.
In mice, a flower oil improved behaviour scores after stress. In cattle, an oil cut tick numbers in a pen trial, and lab work damaged tick nerve tissue. We found no human trial of tagetes oil for any use.
The research in one view
No human trial was found. Everything on the benefits tab comes from test dishes, mice, ticks, mosquito larvae or cattle. These results use far stronger contact than a person would have and do not show what happens in people.
Two sources were read by title only: the 2026 mosquito-larvae paper and the aromatherapist case report. Nothing beyond the title is claimed for them.
Species, plant parts and bottles are different things
Oils in the papers differ a great deal: the leading compounds were tagetone and ocimenone (Argentina), beta-ocimene (South African flowers), cis-beta-ocimene and tagetenones (Pakistan) and dihydrotagetone (a Brazilian cattle-trial oil). Lab germ results differ about 100-fold between papers.
The EU limit depends on alpha-terthienyl content, which a label rarely states. Poison Control says it can be hard to know the species, strength or contaminants in a bottle.
What regulators say
The EU safety committee (2016, phototoxicity only) set the cap above and barred sunscreen use. We read only the abstract and did not check whether the cap became a legal limit.
The US FDA says aromatherapy products marketed to treat or relieve conditions are making drug claims. We did not find or read a statement from IFRA, LiverTox, LactMed, EMA or NCCIH about this oil.
At a glance
Traditional uses history, not proof
- A 2018 review says parts of Tagetes plants are used in folk medicine for dental, stomach, intestinal, emotional and nervous complaints and muscle pain.
- Tagetes plants are used as traditional pest control in homes and plantations.
- This is plant use, mostly as extracts, and is not proof that the oil works or is safe.
Studied for research
- Slowing bacteria and biofilm in test dishes, insufficient
- Cleaning dairy-farm surfaces, lab nanocapsules, insufficient
- Antioxidant action in test tubes, insufficient
- Depressive-like behaviour in mice, very-low
- Killing ticks and mosquito larvae, very-low
- Folk uses of Tagetes plants, insufficient
Main compounds
- Alpha-terthienyl, a light-activated thiophene behind the sun warning
- Tagetone and dihydrotagetone, main compounds in some oils
- Ocimenones and tagetenones, leading compounds in other oils
- Beta-ocimene and beta-pinene, found in several oils
Common forms
- Essential oil (flowers or the plant, depending on the study)
- Perfumery and cosmetic ingredient
- Plant extracts (a different product)
- Pest-control studies (cattle, ticks, mosquito larvae)
Research links: EU safety committee (SCCS) opinion on tagetes oils (abstract) · Poison Control: Essential oils · Pet Poison Helpline: Essential oils · Marigold contact allergens in guinea pigs (abstract) · Tagetes essential oils and extracts, review (abstract) · US FDA: Aromatherapy · GBIF: Tagetes minuta · Research Library · Genes & Biomarkers Library
What it is and its history
- Accepted scientific name
- Tagetes minuta
- Naming authority
- L.
- Common names
- Tagetes oil (English); Marigold oil (English); Wild marigold (T. minuta) (English); French marigold (T. patula) (English)
- Family or group
- Asteraceae (the daisy family; the older name Compositae is used in the 1995 paper), per GBIF.
- Classification
- Plantae > Tracheophyta > Magnoliopsida > Asterales > Asteraceae > Tagetes > Tagetes minuta
- Native range
- A 2018 review says Tagetes is native to America and now grown in Africa, Asia and Europe.
- Habitat
- Not checked in a source read.
- What it looks like
- Part used: Papers describe oil from the flowers (South African study) and from the plant in general; roots are the richest in thiophenes. Which parts go into commercial oil was not found. This page does not describe how to recognise the plant.
- Look-alikes and adulterants
- Name: Calendula (pot marigold); Note: A different plant with its own page; not the same as tagetes.; Name: Other Tagetes species (T. erecta, T. patula, T. tenuifolia, T. lucida); Note: Different thiophene content (T. lucida and T. tenuifolia highest in total in one study), so results do not carry between species.
- Sustainability and conservation
- Not checked (no IUCN or CITES source read).
Photographs
Traditional use and history history, not clinical proof
| Tradition or era | Documented use | Source |
|---|---|---|
| Folk medicine (various parts) | A 2018 review says parts of Tagetes species are used in folk medicine for dental, stomach, intestinal, emotional and nervous disorders and muscular pain. | Salehi et al. 2018 (abstract) |
| Traditional pest control | Tagetes plants are used in households and plantations to control pests, and the thiophenes in the roots are valued as natural pesticides. | Cepeda et al. 2023; Marotti et al. 2010 (abstracts) |
| Perfumery | The SCCS assessed the oils and extracts as fragrance ingredients in cosmetic products. | SCCS 2016 (abstract) |
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 |
|---|---|---|---|---|
| Alpha-terthienyl PubChem 65067 | thiophene | Roots (thiophenes overall); present in some oils SCCS cap: no more than 0.35% in the oil for the cosmetic limit. Typical content of oils was not read. | Light-activated: in a dish with UVA, it killed hamster lung cells. Also a marigold skin sensitiser in guinea pigs. No effect in people was read. 24 18 15 14 8 9 | Laboratory |
| 5-(3-buten-1-ynyl)-2,2'-bithienyl (BBT) | thiophene | Roots The main thiophene in a six-species Italian study; 98% of the thiophene yield in T. minuta. | A moderate to strong skin sensitiser in guinea pigs. Whether it passes into the steam-distilled oil was not found. 15 8 | Animal research |
| Tagetone and dihydrotagetone PubChem 91103 | monoterpene ketone | Essential oil Dihydrotagetone 54.10% and tagetone 6.73% in a Brazilian cattle-trial oil; (E)-tagetone leading in an Argentine oil. Varies by oil. | Named as main components of oils that were germ-slowing in the lab or tick-killing; the single compounds were not tested in these abstracts. CID is for tagetone only. 24 1 5 | Laboratory |
| Ocimenones and tagetenones | monoterpene ketone | Essential oil (Z)-ocimenone among the most abundant in the Argentine oil; trans-tagetenone 23.1% and cis-tagetenone 17.7% in the Pakistani oil. | Part of oils that slowed bacteria and biofilm in test dishes. No effect in people. No CID checked (a PubChem name lookup for ocimenone returned an aldehyde, not the ketone). 5 11 | Laboratory |
| Beta-ocimene PubChem 18756 | monoterpene hydrocarbon | Essential oil (flowers) 14.40% in South African flower oil; cis form 29.1% in a Pakistani oil; 5.11% in a Brazilian oil. | The leading compound in two oils that slowed bacteria in test dishes. No effect in people. 24 10 11 1 | Laboratory |
| Beta-pinene PubChem 14896 | monoterpene hydrocarbon | Essential oil Among the three most abundant in the Argentine oil; amounts not given in the abstract. | Present in an oil that slowed bacteria in a dish. No effect in people. 24 5 | Laboratory |
Mechanisms, receptors and pathways
| Target or pathway | Gene or receptor | What was found | Level |
|---|---|---|---|
| Light-activated cell damage by alpha-terthienyl | Not specified | With UVA light, alpha-terthienyl produced reactive oxygen species, damaged membranes and killed hamster lung cells in a dish; some cell death also happened without light at higher concentrations. 14 9 | Laboratory research |
| Bacterial membrane disruption (test dish) | Not specified | The Argentine oil changed bacterial surface charge, raised membrane permeability up to 90% and changed model-membrane properties. 5 | Laboratory research |
| Bacterial signalling (quorum sensing) and biofilm (test dish) | Quorum-sensing genes of P. aeruginosa PAO1 | The oil cut virulence factors and biofilm without killing the cells, according to the authors. 11 | Laboratory research |
| Brain stress signals in mice | BDNF, PI3K, Akt, ERK2 mRNA | The flower oil restored these signals and lowered oxidative stress and corticosterone in stressed or inflamed mice. 4 | Animal research |
Absorption, metabolism and elimination
- Absorption
- Not established in the sources read.
- Distribution
- Not established.
- Metabolism
- Not established.
- Elimination
- Not established.
- Bioavailability
- Not established. How much alpha-terthienyl reaches or stays in skin was not found.
Isolated compounds versus whole extracts
The oil is a mixture whose make-up depends on species, plant part and place. The thiophenes that drive the sun and allergy warnings are most abundant in roots, while oils analysed in the papers were led by ketones and ocimene. A result for one compound, root extract or oil does not describe another.
Nutritional composition
Tagetes oil is not a nutrient and is not an ingredient to swallow for health. Marigold flower extracts sold for lutein (an eye pigment) are a different product from this essential oil.
2 very low certainty4 not enough evidence
What is Tagetes (Marigold) Oil good for?
The uses people ask about and how strong the evidence is for each. Read the certainty label first: nothing here has been tested in people, and nothing is better than very low.
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.
Slowing bacteria and biofilm in test dishes (laboratory)
Not enough evidenceIn test dishes, tagetes oil slowed several bacteria and cut the slimy film (biofilm) that one bacterium forms. This is lab work only. It does not show the oil treats any infection in people.
3 studiesNot covered. This page gives no amounts and no way to use the oil.
Studies, doses and limits
What the trials found
None found. We searched PubMed for human trials of tagetes oil and found none.
Results
Argentine T. minuta oil: E. coli MIC 17 mg/mL; S. aureus MIC 8.5 mg/mL (membrane permeability up to 90%). South African flower oil: MICs 0.06 to 0.125 mg/mL across seven bacteria. Pakistani oil: biofilm of P. aeruginosa cut by up to 79%, but killing was weak (MIC 325 ug/mL, MBC 5000 ug/mL).
Effect sizes as reported
Test-tube MIC, MBC and percent-inhibition values only. The numbers differ about 100-fold between papers, so the oils or methods are not comparable.
Why this rating
Laboratory work only, on a few bacteria, with oils of different make-up. No animal-to-human step has been shown.
Form and dose studied
Not covered. This page gives no amounts and no way to use the oil.
Who was studied
None (laboratory bacteria).
Limits
Concentrations in a dish are far from what skin or a body would meet. Nothing here tests safety.
Why researchers looked
Researchers screen many plant oils as possible natural germ-fighters because some germs resist drugs.
Traditional use
A 2017 paper says Tagetes minuta has a long record of human use for stomach and intestinal illness; it gives no source and no trial.
Proposed mechanism Preliminary mechanism
An Argentine oil disturbed the bacterial membrane (more permeable, changed charge) in test dishes. A Pakistani oil reduced biofilm by interfering with bacterial signalling, not by killing the cells, according to the authors.
A proposed mechanism does not show that the effect happens in people.
Slowing bacteria in a dish does not make the oil safe or useful on skin. See the Safety tab: sun-triggered skin reactions come first.
Cleaning dairy-farm surfaces (laboratory, nanocapsules)
Not enough evidenceA 2026 lab study packed tagetes oil into tiny capsules and tested it as a teat disinfectant for dairy farms. It worked on some bacteria and surfaces and failed against one when dirt was present.
1 studiesNot covered. This page gives no amounts and no way to use the oil.
Studies, doses and limits
What the trials found
None. A lab and farm-hygiene study.
Results
Capsules (about 267 nm) were stable for 60 days. MIC against S. aureus was 50% (v/v). Disinfectant activity against P. aeruginosa was shown at 5, 15 and 30 minutes on clean surfaces and on rubber, steel and ceramic; against S. aureus at 15 and 30 minutes on clean surfaces. With organic matter present only P. aeruginosa was controlled.
Effect sizes as reported
No effect sizes; time-kill results at stated times.
Why this rating
One lab study, online ahead of print when read, of a special capsule form.
Form and dose studied
Not covered. This page gives no amounts and no way to use the oil.
Who was studied
None (lab surfaces).
Limits
A nanocapsule, not a plain oil. Not tested on animals or people in this paper.
Why researchers looked
Dairy farms look for natural alternatives to disinfectants against mastitis (udder infection) germs.
Traditional use
None.
Proposed mechanism Preliminary mechanism
Not established in the abstract.
A proposed mechanism does not show that the effect happens in people.
A farm disinfectant test, not a product for people. It does not show the oil is safe for skin.
Antioxidant action in test tubes (laboratory)
Not enough evidenceIn chemical tests, oil from the flowers of Tagetes minuta mopped up free radicals. That is a test-tube property, not a proven effect in the body.
1 studiesNot covered. This page gives no amounts and no way to use the oil.
Studies, doses and limits
What the trials found
None.
Results
One South African flower oil (98 compounds, beta-ocimene main): IC50 2.45 mg/mL (DPPH), 2.76 mg/mL (ABTS), 3.23 mg/mL (lipid peroxidation).
Effect sizes as reported
Test-tube IC50 values only.
Why this rating
One lab paper on one oil; no link to any health outcome.
Form and dose studied
Not covered. This page gives no amounts and no way to use the oil.
Who was studied
None (laboratory).
Limits
A 2018 review also lists antioxidant activity for Tagetes extracts, but that is for extracts of plant parts, not this oil.
Why researchers looked
Antioxidant tests are a cheap first screen for plant oils.
Traditional use
None.
Proposed mechanism Preliminary mechanism
Chemical radical-scavenging assays (DPPH, ABTS, lipid peroxidation).
A proposed mechanism does not show that the effect happens in people.
An antioxidant result in a test tube is not a health benefit.
Depressive-like behaviour in mice (animal study)
Very low certaintyIn one mouse study, flower oil of Tagetes minuta improved behaviour scores in mice made stressed or inflamed. It was not tested in people.
1 studiesNot covered. This page gives no amounts and no way to use the oil.
Studies, doses and limits
What the trials found
None.
Results
Depressive-like behaviour caused by restraint stress or an inflammatory challenge was reversed in mice, with the lab changes listed above.
Effect sizes as reported
No numbers in the abstract.
Why this rating
A single mouse study; mouse behaviour tests are weak predictors of human mood effects; no human data.
Form and dose studied
Not covered. This page gives no amounts and no way to use the oil.
Who was studied
Mice only.
Limits
The authors call the oil promising for depression strategies, which goes beyond what a mouse test can show.
Why researchers looked
Researchers looked for oils that lower oxidative stress and inflammation in the brain.
Traditional use
The 2018 review lists emotional and nervous disorders among folk uses of Tagetes plants; it is not evidence for the oil.
Proposed mechanism Preliminary mechanism
In mice the oil reduced hippocampal oxidative stress, lowered plasma corticosterone and restored brain signals (BDNF, PI3K, Akt, ERK2), according to the authors.
A proposed mechanism does not show that the effect happens in people.
Mice were given the oil by stomach tube. This page never suggests swallowing an essential oil.
Killing ticks and mosquito larvae (lab and cattle pen)
Very low certaintyTagetes oil damages ticks and is studied against mosquito larvae. One cattle-pen trial found far fewer ticks on treated cattle. This is pest control, not a health use for people.
3 studiesNot covered. This page gives no amounts and no way to use the oil.
Studies, doses and limits
What the trials found
None. Cattle, ticks and mosquito larvae only.
Results
Cattle pen trial (cattle tick): all tick measures changed, with 99.98% efficacy against the control group for the concentration tested. Brown dog ticks: nerve tissue damage like that seen with the comparison drug amitraz. 2026 mosquito-larvae paper: title only, no results read.
Effect sizes as reported
99.98% efficacy vs control in the cattle trial (authors' figure).
Why this rating
One controlled trial, in cattle, and lab work on ticks; the mosquito paper was not read beyond its title.
Form and dose studied
Not covered. This page gives no amounts and no way to use the oil.
Who was studied
Cattle, ticks, mosquito larvae. No people.
Limits
No safety outcome for the treated animals is in the abstract. This page gives no way to use the oil on animals.
Why researchers looked
Tagetes plants are used as traditional pest control, and ticks resist many synthetic drugs.
Traditional use
A 2018 review says Tagetes plants are used as traditional pest control in homes and plantations.
Proposed mechanism Preliminary mechanism
In brown dog ticks the oil damaged cells of the nervous tissue (synganglion) under the microscope.
A proposed mechanism does not show that the effect happens in people.
Being toxic to ticks and larvae does not show the oil is safe for pets, children or skin.
Folk uses of Tagetes plants (review)
Not enough evidenceA 2018 review lists folk uses of Tagetes plants for dental, stomach, intestinal, emotional and nervous problems and muscle pain. It also reports lab antioxidant, anti-inflammatory and enzyme-blocking activity of plant extracts.
1 studiesNot covered. This page gives no amounts and no way to use the oil.
Studies, doses and limits
What the trials found
None in the abstract.
Results
The review covers traditional use, food preservation and antimicrobial activity. No human trial is described in the abstract.
Effect sizes as reported
None.
Why this rating
A narrative review of mostly lab work on extracts of several species.
Form and dose studied
Not covered. This page gives no amounts and no way to use the oil.
Who was studied
None specific.
Limits
Mixes species and plant parts. Tradition is not proof of benefit or safety.
Why researchers looked
Researchers collect traditional uses to find leads for lab work.
Traditional use
Different parts of different Tagetes species, mostly as extracts and teas, not the essential oil.
Proposed mechanism Preliminary mechanism
Lab activity of extracts as summarised by the review.
A proposed mechanism does not show that the effect happens in people.
Folk use is not safety data. Thiophenes in the plant are the reason for the sun and allergy cautions.
Connections to the rest of health
How Tagetes (Marigold) 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 |
|---|---|---|---|---|
| Immune Support | Not enough evidence | Slowing bacteria and biofilm in test dishes (laboratory): In test dishes, tagetes oil slowed several bacteria and cut the slimy film (biofilm) that one bacterium forms. This is lab work only. It does not show the oil treats any infection in people. Antioxidant action in test tubes (laboratory): In chemical tests, oil from the flowers of Tagetes minuta mopped up free radicals. That is a test-tube property, not a proven effect in the body. | 5 10 11 | |
| Mood Balance | Very low certainty | Depressive-like behaviour in mice (animal study): In one mouse study, flower oil of Tagetes minuta improved behaviour scores in mice made stressed or inflamed. It was not tested in people. | 4 |
B. Body systems
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Immune System | Biological association | Not enough evidence | Studied for: Slowing bacteria and biofilm in test dishes (laboratory) Studied for: Antioxidant action in test tubes (laboratory) | 5 10 11 |
| Nervous System | Biological association | Very low certainty | Studied for: Depressive-like behaviour in mice (animal study) | 4 |
| Skin | Biological association | Not enough evidence | Studied for: Folk uses of Tagetes plants (review) | 17 |
E. Health conditions
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Photosensitivity of skin | Adverse effect or risk | Documented risk | SCCS 2016: cosmetic cap, no sunscreen use. No human case series of the oil found. Preparation or compound: Tagetes oil (alpha-terthienyl) on skin before sun |
18 |
| Contact dermatitis | Adverse effect or risk | Documented risk | One aromatherapist case report (title only); three marigold sensitisers in guinea pigs. Preparation or compound: Tagetes oil and marigold chemicals on skin |
3 8 |
| Pregnancy | Not enough evidence | Safety in pregnancy not clearly demonstrated; no tagetes-specific data found. Preparation or compound: Essential oils in general |
13 |
I. Biomarkers
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Bacterial growth and biofilm in test dishes (MIC, MBC, % biofilm) | Biological association | Not enough evidence | Measured in trials: decrease (growth, biofilm). A lab change is not the same as a health benefit. | 5 10 11 |
| Antioxidant test values (DPPH, ABTS, lipid peroxidation IC50) | Biological association | Not enough evidence | Measured in trials: lower IC50 = stronger test-tube effect. A lab change is not the same as a health benefit. | 10 |
| Mouse behaviour tests and brain stress markers | Biological association | Very low certainty | Measured in trials: improved in treated mice. A lab change is not the same as a health benefit. | 4 |
| Tick counts, weight, egg weight and larval viability | Biological association | Very low certainty | Measured in trials: decrease. A lab change is not the same as a health benefit. | 1 |
L. Active compounds
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Alpha-terthienyl | Biological association | Laboratory | Light-activated: in a dish with UVA, it killed hamster lung cells. Also a marigold skin sensitiser in guinea pigs. No effect in people was read. Preparation or compound: Roots (thiophenes overall); present in some oils |
24 18 15 14 8 9 |
| 5-(3-buten-1-ynyl)-2,2'-bithienyl (BBT) | Biological association | Animal | A moderate to strong skin sensitiser in guinea pigs. Whether it passes into the steam-distilled oil was not found. Preparation or compound: Roots |
15 8 |
| Tagetone and dihydrotagetone | Biological association | Laboratory | Named as main components of oils that were germ-slowing in the lab or tick-killing; the single compounds were not tested in these abstracts. CID is for tagetone only. Preparation or compound: Essential oil |
24 1 5 |
| Ocimenones and tagetenones | Biological association | Laboratory | Part of oils that slowed bacteria and biofilm in test dishes. No effect in people. No CID checked (a PubChem name lookup for ocimenone returned an aldehyde, not the ketone). Preparation or compound: Essential oil |
5 11 |
| Beta-ocimene | Biological association | Laboratory | The leading compound in two oils that slowed bacteria in test dishes. No effect in people. Preparation or compound: Essential oil (flowers) |
24 10 11 1 |
| Beta-pinene | Biological association | Laboratory | Present in an oil that slowed bacteria in a dish. No effect in people. Preparation or compound: Essential oil |
24 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).
The evidence
The research centre for Tagetes (Marigold) 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 read the abstracts of 16 PubMed papers (two more by title only), the Poison Control, Pet Poison Helpline and US FDA pages, and checked plant names in GBIF and compounds in PubChem. We did not read the full EU opinion or any IFRA, LiverTox or LactMed statement.
Study library: every study we checked 24
| Study | Design | People | Product, dose, length | Result |
|---|---|---|---|---|
| Andreotti 2013 Protective action of Tagetes minuta (Asteraceae) essential oil in the control of Rhipicephalus microplus (Canestrini, 1887) (Acari: Ixodidae) in a cattle pen trial. Vet Parasitol · PMID 23778081 · DOI |
Randomized controlled trial in cattle (pen trial) cattle |
Cattle infested with the cattle tick | Tagetes minuta essential oil applied to cattle not stated in the abstract n/a n/a · vs n/a |
Main compounds: dihydrotagetone 54.10%, limonene 6.96%, tagetone 6.73%, beta-ocimene 5.11%. Treatment changed all tick measures; the authors report 99.98% efficacy against the control group at the concentration they tested. Large fall in tick measures in treated cattle Methods, limits and fundingOutcomes: Tick numbers, tick weight, egg weight, larval viability Limitations: A farm-animal pest-control trial, not a test in people or pets. It does not show the oil is safe on skin or fur, and no safety outcome is in the abstract. Authors suggest it as a tick control agent. Funding and conflicts: Research support, non-U.S. government; competing interests not stated in the abstract. Read: abstract |
| Beranek 2026 Enhancing larvicidal activity through selective propagation of Tagetes minuta L. (Asteraceae) essential oil chemotypes against Aedes aegypti. Chemosphere · PMID 42556231 · DOI |
Laboratory study (mosquito larvae), title only laboratory |
Aedes aegypti mosquito larvae | Tagetes minuta essential oil chemotypes not stated n/a n/a · vs n/a |
PubMed holds no abstract for this paper, so no results were read. The title says the study is about larvicidal activity of T. minuta oil chemotypes against Aedes aegypti. Methods, limits and fundingOutcomes: Larvicidal activity (title only) Limitations: Title only: no results, numbers or methods were read, so nothing beyond the title is claimed. Funding and conflicts: Authors declared no competing interests (declaration shown in the PubMed record). Read: title-only |
| Bilsland 1990 Allergic contact dermatitis from the essential oil of French marigold (Tagetes patula) in an aromatherapist. Contact Dermatitis · PMID 2401143 · DOI |
Case report (title only) |
1 One aromatherapist |
Tagetes patula essential oil not stated n/a n/a · vs n/a |
PubMed holds no abstract for this case report, so only its title was read: it reports allergic contact dermatitis from the essential oil of French marigold (Tagetes patula) in an aromatherapist. Methods, limits and fundingOutcomes: Allergic contact dermatitis (title only) Limitations: Title only. Nothing is known here about how the diagnosis was made, which part of the plant was used, or the outcome. Funding and conflicts: Not stated. Read: title-only |
| Birmann 2022 Flower essential oil of Tagetes minuta mitigates oxidative stress and restores BDNF-Akt/ERK2 signaling attenuating inflammation- and stress-induced depressive-like behavior in mice. Brain Res · PMID 35219720 · DOI |
Animal study (mice) mouse |
Mice given restraint stress or an inflammatory challenge (LPS) | Tagetes minuta flower essential oil, given by stomach tube flower two dose levels by stomach tube (not repeated here) n/a · vs n/a |
The oil reversed depressive-like behaviour in stressed or inflamed mice, reduced oxidative stress in the hippocampus, lowered plasma corticosterone and restored mRNA levels of BDNF, PI3K, Akt and ERK2. The authors call it "promising" for new strategies. Behaviour test scores improved in mice Methods, limits and fundingOutcomes: Depressive-like behaviour, hippocampal oxidative stress, plasma corticosterone, brain gene signals (BDNF, PI3K, Akt, ERK2) Limitations: Mice, given by stomach tube. Says nothing about safety or benefit in people, and this page does not suggest swallowing any essential oil. Funding and conflicts: Research support, non-U.S. government; no competing interest stated in the abstract. Read: abstract |
| Bordon 2025 Antimicrobial Action of Essential Oil of Tagetes minuta: Role of the Bacterial Membrane in the Mechanism of Action. Antibiotics (Basel) · PMID 40723935 · DOI |
Laboratory study laboratory |
Bacteria (E. coli, S. aureus) and model lipid membranes | Tagetes minuta essential oil not stated in the abstract n/a n/a · vs n/a |
27 compounds identified; (E)-tagetone, (Z)-ocimenone and beta-pinene were the most abundant. E. coli: MIC and MBC 17 mg/mL. S. aureus: MIC 8.5 mg/mL, MBC above 17 mg/mL. The oil raised the zeta potential by more than 9 mV and increased membrane permeability up to 90%. In model membranes it lowered the dipole potential and transition temperature. Slowed and killed two bacteria in the dish at high concentrations; more effective against E. coli Methods, limits and fundingOutcomes: Antibacterial activity, membrane permeability and membrane properties Limitations: Test-tube work with two bacteria. High concentrations. Nothing about people, skin or safety. Funding and conflicts: Authors declared no competing interests. Read: abstract |
| Cepeda 2023 Effect of Tagetes minuta essential oil on the central nervous system of unfed Rhipicephalus sanguineus sensu lato 'tropical lineage' ticks. Exp Appl Acarol · PMID 37985606 · DOI |
Laboratory study (ticks) laboratory |
Unfed adult brown dog ticks (R. sanguineus s.l.) | Tagetes minuta essential oil not stated in the abstract n/a n/a · vs n/a |
The oil caused cell damage in the tick synganglion (swelling, loss of shape, vacuoles, chromatin changes), as did the comparison tick drug amitraz. 21 compounds found; (Z)-beta-ocimene, ocimene, (Z)-tagetone and verbenone were the main ones. Tick nerve tissue was damaged in the lab Methods, limits and fundingOutcomes: Damage to the tick nervous system (synganglion) under the microscope Limitations: Lab study on ticks. Shows the oil is active against ticks, which is not the same as being safe for pets or people. Funding and conflicts: Not stated in the abstract. Read: abstract |
| Grosu Dumitrescu 2024 New Insights Concerning Phytophotodermatitis Induced by Phototoxic Plants. Life (Basel) · PMID 39202761 · DOI |
Narrative review review |
Reports on plant-triggered sun reactions | Phototoxic plants in general n/a n/a n/a · vs n/a |
Phytophotodermatitis is a non-immune skin reaction triggered by certain plants followed by sunlight (UV). Plant chemicals (for example furanocoumarins and psoralens) plus UV can cause redness, fluid blisters, swelling and darkening of the skin. The review names preventive measures such as long-sleeved clothing and gloves. An erratum was issued in 2025. Methods, limits and fundingOutcomes: Mechanism and management of phytophotodermatitis Limitations: The abstract does not mention Tagetes or alpha-terthienyl and names furanocoumarins as the culprits. Used only to describe what a sun-triggered plant skin reaction looks like. Funding and conflicts: Authors declared no conflicts of interest. Read: abstract |
| Hausen 1995 Butenylbithiophene, alpha-terthienyl and hydroxytremetone as contact allergens in cultivars of marigold (Tagetes sp.). Contact Dermatitis · PMID 7493459 · DOI |
Animal sensitisation experiments (guinea pigs) guinea pig |
Guinea pigs | Short ether extracts and isolated compounds of Tagetes (ornamental marigold) cultivars plant material (not an essential oil) n/a n/a · vs n/a |
Three constituents were identified as contact allergens: 5-(3-buten-1-ynyl)-2,2'-bithiophene (moderate to strong sensitiser), alpha-terthienyl (less strong) and hydroxytremetone (weak). The authors say thiophenes common in the daisy family (Compositae) have sensitising properties as well as phototoxic ones. Three marigold chemicals sensitised guinea pigs Methods, limits and fundingOutcomes: Skin sensitising potency of compounds from Tagetes cultivars Limitations: Guinea pigs, and ether extracts of garden marigold cultivars rather than the steam-distilled oil, so it shows the kind of risk and not a rate for the oil. Funding and conflicts: Not stated in the abstract. Read: abstract |
| Hudson 1993 Biological activities of terthiophenes and polyynes from the Asteraceae. Planta Med · PMID 8255937 · DOI |
Laboratory study laboratory |
Microorganisms, viruses and tumour cells in the lab | Terthiophenes and polyynes from daisy-family plants (pure compounds) compounds n/a n/a · vs n/a |
Terthiophenes (the alpha-terthienyl nucleus with simple side chains) showed impressive UVA-dependent activity, some better than alpha-terthienyl itself. Polyynes had no significant activity with or without UVA. Methods, limits and fundingOutcomes: Biological activity with and without UVA light Limitations: Pure compounds in the lab; says nothing about the oil on skin. The authors suggest animal testing, not human use. Funding and conflicts: Research support, non-U.S. government; no competing interest stated in the abstract. Read: abstract |
| Igwaran 2017 Chemical constituents, antibacterial and antioxidant properties of the essential oil flower of Tagetes minuta grown in Cala community Eastern Cape, South Africa. BMC Complement Altern Med · PMID 28676058 · DOI |
Laboratory study laboratory |
Seven bacterial strains; chemical antioxidant tests | Tagetes minuta flower essential oil (Clevenger-type distillation) flower n/a n/a · vs n/a |
98 compounds found; beta-ocimene (14.40%) was the main one. Antioxidant IC50 values: DPPH 2.45 mg/mL, ABTS 2.76 mg/mL, lipid peroxidation 3.23 mg/mL. MICs: 0.125 mg/mL for S. aureus, M. smegmatis and S. uberis; 0.06 mg/mL for L. ivanovii, Vibrio spp., E. cloacae and E. coli. All seven bacteria were slowed in the dish Methods, limits and fundingOutcomes: Chemical composition, antioxidant tests (DPPH, ABTS, lipid peroxidation), antibacterial MIC and MBC Limitations: Test-tube work. The abstract says the oil "may be a useful candidate" for finding new lead compounds, which is not a finding in people. MIC values differ widely from other papers (0.06 vs 17 mg/mL), so the oils or the methods differ. Funding and conflicts: Authors declared no competing interests. Read: abstract |
| Khan 2023 Essential Oil from Tagetes minuta Has Antiquorum Sensing and Antibiofilm Potential against Pseudomonas aeruginosa Strain PAO1. ACS Omega · PMID 37810677 · DOI |
Laboratory study laboratory |
Pseudomonas aeruginosa strain PAO1 (a lab strain) | Tagetes minuta essential oil (steam distillation) not stated in the abstract n/a n/a · vs n/a |
Main compounds: cis-beta-ocimene 29.1%, trans-tagetenone 23.1%, cis-tagetenone 17.7%. Biofilm formation was inhibited by up to 79%. Killing of the bacteria was "not so promising" (MIC 325 ug/mL, MBC 5000 ug/mL). The authors say biofilm was reduced by interfering with bacterial signalling, not by killing cells. Biofilm reduced in the dish; weak germ-killing Methods, limits and fundingOutcomes: Biofilm, virulence factors, antibacterial MIC and MBC Limitations: One lab bacterial strain. Test-tube concentrations do not tell us what happens on skin or in the body. Funding and conflicts: Authors declared no competing financial interest. Read: abstract |
| Ključevšek 2025 Allergic Potential of Medicinal Plants From the Asteraceae Family. Health Sci Rep · PMID 39995792 · DOI |
Narrative review review |
Reports on Asteraceae medicinal plants | Asteraceae (daisy family) medicinal plants in general n/a n/a n/a · vs n/a |
Asteraceae are important sensitisers, causing immediate and delayed hypersensitivity. Pollen panallergens (mainly ragweed and mugwort) cause cross-reactions. Sesquiterpene lactones can cause skin irritation and inflammation, and may cause systemic reactions after ingestion in sensitised people. Extensive cross-reactivity among sesquiterpene lactones is reported; the authors say many uncertainties remain. Methods, limits and fundingOutcomes: Allergic potential of Asteraceae plants Limitations: The abstract does not name Tagetes. The marigold allergens identified in the guinea pig study were thiophenes, not sesquiterpene lactones, so this review shows the family risk, not the oil's. Funding and conflicts: Authors declared no conflicts of interest. Read: abstract |
| Lis-Balchin 1999 Possible health and safety problems in the use of novel plant essential oils and extracts in aromatherapy. J R Soc Promot Health · PMID 10673845 · DOI |
Narrative review review |
Aromatherapy practice | Essential oils in general n/a n/a n/a · vs n/a |
The author says most commonly used essential oils in massage are seldom dangerous, with low systemic toxicity at 2% dilution if not adulterated, but safety during pregnancy, childbirth and babies has not been clearly demonstrated. Sensitisation is a growing concern, and some novel oils are potentially toxic. Methods, limits and fundingOutcomes: Safety of aromatherapy oils Limitations: A 1999 review of oils in general; it does not mention Tagetes. The 2% figure is the author's statement about common oils and is not advice for tagetes oil. Funding and conflicts: Not stated in the abstract. Read: abstract |
| Luan 2018 Photosensitization of Chinese hamster V79 cells to photoactivated alpha-terthienyl involving membrane damage and oxidative stress. J Photochem Photobiol B · PMID 29957498 · DOI |
Laboratory study (cell culture) laboratory |
Chinese hamster V79 lung fibroblast cells | Alpha-terthienyl (pure compound) with or without black-light UVA compound see results (lab concentrations) 15 minutes of light · vs non-photosensitising condition |
After 15 minutes of UVA (320-400 nm) light, alpha-terthienyl caused the cells to shrink, detach and die, with an IC50 of 4.78 ug/mL; viability fell to 10.58% of control at 10.0 ug/mL. Reactive oxygen species and a membrane-damage marker rose with light time and concentration. Cell death and oxidative stress were also seen without light at above 7.0 ug/mL. Light-activated cell killing in a dish Methods, limits and fundingOutcomes: Cell survival, reactive oxygen species, membrane damage Limitations: Pure compound on hamster cells, not tagetes oil on human skin. It shows the mechanism behind the sun warning, not the size of the risk from the oil. Funding and conflicts: Not stated in the abstract. Read: abstract |
| Marotti 2010 Thiophene occurrence in different Tagetes species: agricultural biomasses as sources of biocidal substances. J Sci Food Agric · PMID 20394003 · DOI |
Plant chemistry study plant |
Six Tagetes species grown in northern Italy | Roots, shoots and flowers of T. erecta, T. filifolia, T. lucida, T. minuta, T. patula, T. tenuifolia roots, shoots, flowers n/a n/a · vs n/a |
Roots had the highest diversity and content of thiophenes (64 to 100% of the total). The main one was 5-(3-buten-1-ynyl)-2,2'-bithienyl (BBT), followed by BBTOAc, alpha-terthienyl (alpha-T) and BBTOH. T. minuta had the highest total thiophene yield, with BBT 98% of it. Methods, limits and fundingOutcomes: Thiophene content by plant part and species Limitations: Plant material, not distilled oil. The abstract does not say how much alpha-terthienyl ends up in a steam-distilled oil, which is the amount the SCCS limit refers to. Funding and conflicts: Research support, non-U.S. government; no competing interest stated in the abstract. Read: abstract |
| Moreira 2026 Preparation, physicochemical characterisation, storage stability and in vitro disinfectant activity of Tagetes minuta (L.) essential oil-loaded polycaprolactone nanocapsules against mastitis pathogens. J Dairy Res · PMID 42831442 · DOI |
Laboratory study laboratory |
Dairy-farm bacteria on lab surfaces (rubber, stainless steel, ceramic) | Tagetes minuta essential oil loaded into nanocapsules not stated in the abstract n/a n/a · vs n/a |
Capsules were about 267 nm across and stable for 60 days. MIC against S. aureus was 50% (v/v). Disinfectant activity against P. aeruginosa was shown at 5, 15 and 30 minutes without organic matter; against S. aureus at 15 and 30 minutes (100% v/v). With organic matter present it worked only against P. aeruginosa. The authors suggest it could be an alternative for teat disinfection in milking. Worked on some bacteria and surfaces in the lab; lost activity against S. aureus when organic matter was present Methods, limits and fundingOutcomes: Capsule properties, storage stability, minimum inhibitory concentration, disinfectant activity Limitations: Lab surfaces only. A specially made nanocapsule form, not a plain oil. Online ahead of print when read, so it may still change. Not a human or consumer product. Funding and conflicts: Not stated in the abstract. Read: abstract |
| Salehi 2018 Tagetes spp. Essential Oils and Other Extracts: Chemical Characterization and Biological Activity. Molecules · PMID 30388858 · DOI |
Narrative review review |
Tagetes species (T. minuta, T. erecta, T. patula, T. tenuifolia) | Tagetes essential oils and extracts various plant parts n/a n/a · vs n/a |
Tagetes is native to America and now grown in Africa, Asia and Europe. Folk uses include dental, stomach, intestinal, emotional and nervous disorders and muscular pain. Extracts show antioxidant, anti-inflammatory and enzyme-inhibitory properties in the lab. The plants are also used for fungicidal, bactericidal and insecticidal purposes in farming. Methods, limits and fundingOutcomes: Traditional use, chemistry, antimicrobial and other lab activity Limitations: The abstract describes no human trial. Covers several species and mostly extracts, so findings do not transfer to one oil. Funding and conflicts: Authors declared no conflicts of interest. Read: abstract |
| Scientific Committee On Consumer Safety 2016 Opinion of the Scientific Committee on Consumer Safety (SCCS) - Opinion on the fragrance ingredients Tagetes minuta and Tagetes patula extracts and essential oils (phototoxicity only) in cosmetic products. Regul Toxicol Pharmacol · PMID 26721339 · DOI |
Regulatory scientific opinion (abstract) regulatory opinion |
Consumers using cosmetic products (phototoxicity question only) | Tagetes minuta and Tagetes patula extracts and essential oils not stated in the abstract n/a n/a · vs n/a |
The SCCS considers a maximum of 0.01% of T. minuta and T. patula extracts and essential oils in leave-on products (except sunscreens) as safe, provided the alpha-terthienyl (terthiophene) content of the extracts and oils does not exceed 0.35%. The extracts and oils should not be used as ingredients of sunscreen products. A 0.01% cap in leave-on cosmetics, alpha-terthienyl no more than 0.35%, none in sunscreens Methods, limits and fundingOutcomes: Phototoxicity risk in cosmetic products Limitations: Abstract only; the full opinion (data, assumptions, and the other safety questions it left aside, such as allergy) was not read. The cap is for cosmetic makers and is not a safe amount for home use. It covers phototoxicity only. Funding and conflicts: EU scientific committee opinion. Read: abstract |
| US Food and Drug Administration 2026 US FDA: Aromatherapy (page read 2026-10-25) n/a · Source |
Regulator web page n/a |
n/a | n/a n/a n/a n/a · vs n/a |
A fragrance product marketed with claims to treat disease or affect the body (for example ease pain, relax muscles, treat depression or anxiety, help sleep) is making drug claims, and a plant origin does not exempt it from drug rules. Cosmetics do not need FDA approval before sale. Page text read does not mention tagetes. Methods, limits and fundingOutcomes: How aromatherapy products are regulated Limitations: General statement about aromatherapy products, not about tagetes. Read: full-text |
| Walker S (veterinary student extern 2026 Pet Poison Helpline: Essential Oils (page read 2026-10-25) n/a · Source |
Animal poison centre education page pets |
n/a | n/a n/a n/a n/a · vs n/a |
Essential oil poisoning can affect all species, but cats and birds are at the greatest risk. Common signs: drooling, vomiting, lethargy, loss of appetite, and irritation of skin, airways and mucous membranes; signs usually appear within 6 to 8 hours. Oral exposure carries the highest risk, then skin, then breathing. High-concentration exposures are more worrying. Its list of oils that can cause poisoning does not name tagetes or marigold; that is not proof of safety. Do not make a pet vomit; call a vet or the helpline. Methods, limits and fundingOutcomes: Essential oil poisoning in pets, in general Limitations: Not specific to tagetes; the list of oils is long and does not name it. Read: full-text |
| n/a 2026 Poison Control (National Capital Poison Center): Essential oils: Poisonous when misused (page read 2026-10-25) n/a · Source |
Poison centre education page n/a |
n/a | n/a n/a n/a n/a · vs n/a |
General essential-oil page, not about tagetes. Says misuse can cause serious poisoning; many oils can cause rashes and some are poisonous if absorbed through the skin or swallowed; aspirating an oil into the lungs can cause pneumonia; children have thin skin and immature livers and may be more susceptible; oils may interact with medications; it can be hard to know the species, concentration or contaminants in a bottle; diluting in a carrier oil is the best way to avoid a bad reaction from direct skin contact and oils should not be used on damaged skin; bottles must be locked out of sight and reach of children and pets; the most common allergic reaction is a skin rash and use should stop if one occurs; difficulty breathing with an allergic reaction is an emergency. Gives no tagetes case. Methods, limits and fundingOutcomes: Safety statements for essential oils in general Limitations: Not specific to tagetes. Read: full-text |
| n/a 2026 GBIF Backbone Taxonomy: Tagetes minuta L. (match API read 2026-10-25) n/a · Source |
Registry or database n/a |
n/a | n/a n/a n/a n/a · vs n/a |
Accepted species name Tagetes minuta L., status ACCEPTED, confidence 99, family Asteraceae, usage key 3088481. Methods, limits and fundingOutcomes: Accepted name and family Read: full-text |
| n/a 2026 GBIF Backbone Taxonomy: Tagetes patula L. (match API read 2026-10-25) n/a · Source |
Registry or database n/a |
n/a | n/a n/a n/a n/a · vs n/a |
Tagetes patula L. is listed as a SYNONYM (confidence 98) of Tagetes erecta (accepted usage key 3088488). The SCCS opinion and several papers still use T. patula as a separate name. Methods, limits and fundingOutcomes: Accepted name and family Limitations: Name use differs between GBIF and the papers read, so the oils sold as T. patula are described here by the name the sources used. Read: full-text |
| n/a 2026 PubChem compound name lookups (read 2026-10-25) n/a · Source |
Registry or database n/a |
n/a | n/a n/a n/a n/a · vs n/a |
PubChem name lookups returned: 2,2':5',2''-terthiophene (alpha-terthienyl) CID 65067, C12H8S3; beta-ocimene CID 18756, C10H16; beta-pinene CID 14896, C10H16; tagetone (2,6-dimethylocta-5,7-dien-4-one) CID 91103, C10H16O. A lookup for ocimenone returned a different compound, so no CID is given for ocimenone. Methods, limits and fundingOutcomes: Compound identifiers Limitations: Identifiers by name match; isomer (E/Z) forms were not separated. Read: full-text |
What we do not know yet
- What the evidence supports: lab germ and antioxidant results (insufficient), and mouse and cattle results (very low). No human trial of any benefit was found.
- The full EU opinion was not read, so typical alpha-terthienyl levels in commercial oils are unknown.
- No patch-test rate, human sun-test, asthma, seizure or hormone data were found.
- No study in pregnancy, breastfeeding, children or pets.
- No LiverTox, LactMed, IFRA, Tisserand, EMA or NCCIH statement was read.
How new research is added
New studies are found by a saved PubMed search and are placed in a review queue. A person reads each one before it is added.
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 4
Bacterial growth and biofilm in test dishes (MIC, MBC, % biofilm)
Decrease (growth, biofilm) in trials
The lowest amount of oil that stops visible bacterial growth (MIC) or kills bacteria (MBC), and how much biofilm forms.
Not enough evidenceResults and what it means
Why it was measured
The main outcome in the lab germ studies.
Statistical vs. clinical meaning
Test-dish values for different oils and methods; they cannot be compared with each other or with a person.
Safety implication
A germ-slowing number says nothing about skin safety.
Antioxidant test values (DPPH, ABTS, lipid peroxidation IC50)
Lower IC50 = stronger test-tube effect in trials
The amount of oil that neutralises half of a test radical in a chemical assay.
Not enough evidenceResults and what it means
Mouse behaviour tests and brain stress markers
Improved in treated mice in trials
Depressive-like behaviour scores, plasma corticosterone, hippocampal oxidative stress and gene signals in mice.
Very low certaintyResults and what it means
Why it was measured
Outcomes of the mouse study.
Statistical vs. clinical meaning
Mouse measures; they do not show a change in human mood.
Safety implication
None for people.
| Study | Result | People | Product |
|---|---|---|---|
| 4 | Behaviour improved, oxidative stress and corticosterone fell, and BDNF, PI3K, Akt and ERK2 mRNA levels were restored in treated mice. |
Tick counts, weight, egg weight and larval viability
Decrease in trials
How many ticks stay on cattle, how heavy they are, and how well their eggs and larvae survive.
Very low certaintyResults and what it means
Why it was measured
Outcomes of the cattle-pen trial.
Statistical vs. clinical meaning
Pest-control outcomes in cattle.
Safety implication
Not a safety result.
| Study | Result | People | Product |
|---|---|---|---|
| 1 | All measures changed significantly; 99.98% efficacy against the control group at the tested concentration (authors' figure). |
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 7
- Sunlight: the EU safety committee sets a cosmetic cap on tagetes oil because of sun-triggered skin damage, and says keep it out of sunscreens.. The EU Scientific Committee on Consumer Safety (SCCS, 2016) assessed Tagetes minuta and Tagetes patula extracts and essential oils for phototoxicity only. It considered 0.01% of the oil in leave-on cosmetics (not sunscreens) safe, provided alpha-terthienyl does not exceed 0.35%, and said these oils should not be used in sunscreens. That is a rule for cosmetic makers, not a safe amount for anyone to try at home, and this page gives no safe amount. Alpha-terthienyl is a light-activated chemical: in lab cells, it killed hamster cells after UVA light. We do not advise putting this oil on skin before sun or a tanning bed. Regulatory opinion 18 14 15
- Skin allergy: marigold chemicals sensitised guinea pigs, and one aromatherapist reacted to French marigold oil.. A 1990 case report (title only) describes allergic contact dermatitis from Tagetes patula essential oil in an aromatherapist. A 1995 guinea pig study found three allergenic chemicals in marigold cultivar extracts, including alpha-terthienyl. Daisy-family plants are known sensitisers. No rate for tagetes oil in the general public was found. Case report 3 8 12
- Do not swallow it. No tagetes poisoning case or safe swallowed amount was found.. Poison Control says some essential oils are poisonous if swallowed or absorbed through the skin, and oil that enters the lungs can cause pneumonia. We found no tagetes poisoning report and no safe amount. A mouse study gave the oil by stomach tube; that is an animal experiment, not a reason to swallow it. If anyone may have swallowed any essential oil, call poison control (US: 1-800-222-1222) or your emergency number. Authoritative guidance 21 4
- Never use it undiluted. No tagetes dilution figure was read.. 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 oils should not go on damaged skin. The only number we read for tagetes oil is the SCCS cosmetic cap, which is not a dilution tip. No Tisserand or IFRA limit for tagetes oil was read, so no home-use amount is given here. Authoritative guidance 21 18
- Pregnancy, breastfeeding, babies and children: no tagetes data, so do not assume it is safe.. A 1999 review says the safety of aromatherapy oils in pregnancy, childbirth and babies has not been clearly demonstrated. Poison Control says children have thin skin and immature livers. We found no study of tagetes oil in any of these groups. Narrative review 13 21
- Pets: cats and birds are at the greatest risk from essential oils in general.. Pet Poison Helpline says cats and birds are at the greatest risk and that its list of poisoning oils does not name tagetes; that is not proof of safety. Tagetes oil is studied for killing ticks and mosquito larvae, which does not show it is safe on pets. Keep bottles out of reach. Authoritative guidance 20 1
- Not calendula: tagetes oil is a different plant and a different product.. Calendula (pot marigold) is a separate plant. Tagetes (French, African or wild marigold) belongs to a different genus. Results and safety statements for one do not carry to the other, and marigold flower extracts sold for lutein are another product again. Plain fact 22
Side effects 5
| Effect | How often | Severity and recovery | Evidence |
|---|---|---|---|
| Sun-triggered skin reaction (phototoxicity) The SCCS set a cosmetic cap and barred sunscreen use because of this risk. We found no human case series of the oil; the sun-reaction description is from a review of phototoxic plants, which does not mention Tagetes. | No rate found for tagetes oil in people | Not graded for tagetes oil. The review of plant-triggered sun reactions describes redness, blisters, swelling and darkening for phototoxic plants in general. Not described for tagetes oil. | Regulatory opinion 18 7 |
| Allergic skin reaction (contact dermatitis) Guinea pigs were sensitised by three chemicals in marigold extracts. Poison Control: stop use and wash off if a rash appears. | One aromatherapist case report; no rate found | Not available (title only). Not available. | Case report 3 8 |
| Poisoning if swallowed; lung damage if breathed in as a liquid (aspiration) A general poison-centre warning for essential oils. | No tagetes case found | Not graded for tagetes oil Not described | Authoritative guidance 21 |
| Breathing problems or asthma from scent No source read covers tagetes oil and asthma, seizures or hormones. | Not found | Not found Not found | Insufficient evidence |
| Poisoning in pets (especially cats and birds) Signs in general: drooling, vomiting, lethargy, skin and airway irritation. | No tagetes case found | Not graded Not described | Authoritative guidance 20 |
Liver
No liver injury linked to tagetes oil was described in the sources we read. LiverTox was not checked for this oil. Poison Control gives swallowed pennyroyal oil as an example of liver poisoning and says children's livers are immature; it does not name tagetes. 21
How often. Not established.
Monitoring. Not applicable.
This is a safety connection. It is not evidence that Tagetes (Marigold) Oil supports liver health.
Medicines and supplements 3
| With | Why it matters | Importance | Evidence | What to do |
|---|---|---|---|---|
| Sunlight (UV), sunbeds and tanning products sunlight | Alpha-terthienyl is a light-activated chemical (lab cells died after UVA with it). The SCCS limits the oil in leave-on products and bars it from sunscreens. | The main practical warning for this oil. | Regulatory opinion Low certainty 18 14 | Do not use tagetes oil on skin that will meet sun or a tanning bed. Ask a pharmacist or dermatologist. |
| Other daisy-family (Asteraceae) plants such as ragweed, mugwort and chamomile, and fragrance allergies allergy | The review describes pollen panallergens and extensive cross-reactions among sesquiterpene lactones. The marigold allergens in the guinea pig study were thiophenes, so cross-reaction with tagetes oil is not shown. | Possible, not measured for tagetes oil. | Narrative review Low certainty 12 8 | If you have a daisy-family or fragrance allergy, tell a pharmacist or doctor before any contact. |
| Prescription and over-the-counter medicines in general unknown | Poison Control says essential oils may interact with medications. No tagetes-specific interaction, and no source about medicines that raise sun sensitivity with this oil, was read. | General statement only. | Authoritative guidance Not enough evidence 21 | Ask a pharmacist. |
Who should check first 5
| Situation | Advice | Evidence |
|---|---|---|
| Skin that will meet sun, a tanning bed or UV treatment | Avoid. This is the SCCS phototoxicity concern. | Regulatory opinion 18 |
| Swallowing the oil, or any contact by babies, young children or pets | Do not swallow. Keep bottles locked away. If swallowed, call poison control. | Authoritative guidance 21 20 |
| Known allergy to marigold, daisy-family plants, fragrances or essential oils; or a past rash after an oil | Avoid. Sensitisation is documented for marigold chemicals. | Narrative review 8 12 3 |
| Damaged or broken skin | Do not apply any essential oil (Poison Control). | Authoritative guidance 21 |
| Pregnancy and breastfeeding | Not shown to be safe. Ask a clinician before any exposure. | Narrative review 13 |
Overdose, product quality and regulators
Summary. No lethal or toxic amount for tagetes oil is described in the sources we read, and none is stated here. The light-activated chemical alpha-terthienyl is the best-described hazard.
Amounts. No safe amount is established, and this page gives none. The only number read is the SCCS cosmetic cap (0.01% of the oil in leave-on products, alpha-terthienyl at or below 0.35%), which is for cosmetic makers.
Onset and course. Not described for tagetes oil.
Repeated use. Repeated skin contact is the route linked to allergy; the one case report was in a working aromatherapist.
Animal data. We read no animal toxicity study of the oil. Lab work shows it damages ticks and bacteria, and photoactivated alpha-terthienyl killed hamster lung cells in a dish (IC50 4.78 ug/mL); the same paper saw cell death at higher concentrations without light.
Toxic parts. In a study of six Tagetes species, roots held 64 to 100% of the thiophenes, with BBT the main one and alpha-terthienyl also present. Which plant part and species a given oil comes from, and how much alpha-terthienyl it holds, is not stated in the abstracts read. The SCCS cap depends on that content.
Not read. The full SCCS opinion, IFRA standards, Tisserand safety data, LiverTox, LactMed, EMA and NCCIH were not read.
What is in a bottle can differ from the label, and tagetes oils differ a lot from each other.
Unknown species, strength and contaminants. Poison Control says essential oils are not well regulated and it can be hard to know the species, concentration or contaminants in a bottle. 21
Composition varies. Papers report different leading compounds: (E)-tagetone, (Z)-ocimenone and beta-pinene (Argentina); beta-ocimene 14.40% (South African flowers); cis-beta-ocimene 29.1% with trans- and cis-tagetenone (Pakistan); dihydrotagetone 54.10% (Brazilian cattle trial). The tick study found (Z)-beta-ocimene, ocimene, (Z)-tagetone and verbenone. 5 10 11 1 6
Species and plant part matter for sun safety. The SCCS limit is tied to the alpha-terthienyl content of the oil, and roots held most of the thiophenes in an Italian study. A label that gives only "marigold" or "tagetes" does not tell you either. 18 15
Different marigolds. Tagetes oils (T. minuta, T. patula and others), calendula (pot marigold) and marigold flower extracts sold for lutein are different products. GBIF lists Tagetes patula as a synonym of Tagetes erecta. 22 23
| Body | Action | Date |
|---|---|---|
| EU Scientific Committee on Consumer Safety (SCCS) (European Union) | 2016 opinion (phototoxicity only): 0.01% of Tagetes minuta and T. patula extracts and essential oils considered safe in leave-on cosmetic products (not sunscreens) if alpha-terthienyl is no more than 0.35%; not for use in sunscreens. source | 2016-04 |
| Poison Control (National Capital Poison Center) (United States) | General warnings on essential oils: poisoning if swallowed or absorbed, pneumonia if aspirated, rash and allergy, children and pets, possible medicine interactions. source | 2026-10-25 |
| Pet Poison Helpline (United States) | General warnings on essential oil poisoning in pets: cats and birds at greatest risk; tagetes not named in its list. source | 2026-10-25 |
| US Food and Drug Administration (FDA) (United States) | Aromatherapy products with claims to treat or relieve conditions are making drug claims; a plant origin does not exempt them. Page does not name tagetes. source | 2026-10-25 |
When to get medical help
- If a child or pet may have swallowed any essential oil, call poison control (US: 1-800-222-1222) or your local emergency number right away. For a pet, call a vet or an animal poison helpline.
- Swelling of the face or throat, trouble breathing, or a spreading rash after contact with an oil needs urgent medical care.
- Choking or coughing after oil is swallowed can mean it has entered the lungs: seek emergency care.
- Redness, burning or blisters on skin that met the oil and then sunlight or a tanning bed: wash the area, keep it out of the sun and see a doctor.
- A rash that appears after use: stop, wash the oil off, and see a doctor if it does not clear.
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 tagetes oil phototoxic?
It can be. The EU safety committee (SCCS, 2016) assessed tagetes oils for phototoxicity only. It considered 0.01% of the oil in leave-on cosmetics (not sunscreens) safe if alpha-terthienyl is no more than 0.35%, and said it should not be in sunscreens. That is a cosmetic maker's limit, not a home-use tip. Avoid putting the oil on skin before sun or a tanning bed.
Can I put tagetes oil on my skin undiluted?
Is tagetes oil safe to swallow?
No. Do not swallow essential oil. Poison Control warns that some oils are poisonous if swallowed and that oil entering the lungs can cause pneumonia. We found no tagetes case, and no safe amount is known. If a child or pet may have swallowed any essential oil, call poison control (US: 1-800-222-1222) or your emergency number.
Can tagetes oil cause an allergy?
Yes, it is documented. A 1990 case report (title only) describes allergic contact dermatitis from French marigold oil in an aromatherapist, and guinea pigs were sensitised by three chemicals from marigold cultivars. Daisy-family plants are known sensitisers. We found no rate for the general public. Stop use and wash off if a rash appears.
Is tagetes oil the same as calendula?
Does tagetes oil help any health condition?
Does tagetes oil kill germs?
In test dishes, yes: oils slowed E. coli, S. aureus and other bacteria, and one cut P. aeruginosa biofilm. The numbers differ about 100-fold between papers. A lab dairy-surface test worked on some bacteria and failed against S. aureus when dirt was present. None of this shows the oil treats an infection in people.
Does tagetes oil repel or kill ticks and mosquitoes?
Is tagetes oil safe in pregnancy, breastfeeding or for children?
Is tagetes oil safe for cats, dogs and birds?
Does tagetes oil interact with medicines?
No tagetes-specific interaction was found. Poison Control says essential oils may interact with medications, and we did not read any source on medicines that raise sun sensitivity with this oil. Ask a pharmacist.
What is in tagetes oil, and are all bottles the same?
No. Papers name tagetone, dihydrotagetone, ocimenones, tagetenones, beta-ocimene and beta-pinene, but the leading compound differed between oils. The sun warning depends on alpha-terthienyl, which is richest in roots, and a label may not state it. Poison Control says it can be hard to know what is in a bottle.
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 read the abstracts of 16 PubMed papers (two more by title only), the Poison Control, Pet Poison Helpline and US FDA pages, and checked plant names in GBIF and compounds in PubChem. We did not read the full EU opinion or any IFRA, LiverTox or LactMed statement.
- 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. Funding is labelled where the abstract gave it.
Sources 24
Each source was opened and checked. Where we read only the abstract, it says so. The small numbers in the text point here.
- Andreotti R, Garcia MV, Cunha RC, Barros JC. Protective action of Tagetes minuta (Asteraceae) essential oil in the control of Rhipicephalus microplus (Canestrini, 1887) (Acari: Ixodidae) in a cattle pen trial.. Vet Parasitol. 2013. PMID 23778081. DOI 10.1016/j.vetpar.2013.04.045. (abstract)
- Beranek M, Massuh Y, Batallan PG, Konigheim BS. Enhancing larvicidal activity through selective propagation of Tagetes minuta L. (Asteraceae) essential oil chemotypes against Aedes aegypti.. Chemosphere. 2026. PMID 42556231. DOI 10.1016/j.chemosphere.2026.145060. (title-only)
- Bilsland D, Strong A. Allergic contact dermatitis from the essential oil of French marigold (Tagetes patula) in an aromatherapist.. Contact Dermatitis. 1990. PMID 2401143. DOI 10.1111/j.1600-0536.1990.tb00091.x. (title-only)
- Birmann PT, Casaril AM, Zugno GP, Acosta GG, Severo Sabedra Sousa F, Collares T, Seixas FK, Jacob RG, Bruning CA, Savegnago L, Hartwig D. Flower essential oil of Tagetes minuta mitigates oxidative stress and restores BDNF-Akt/ERK2 signaling attenuating inflammation- and stress-induced depressive-like behavior in mice.. Brain Res. 2022. PMID 35219720. DOI 10.1016/j.brainres.2022.147845. (abstract)
- Bordon A, Rodriguez SA, Chaves DSA, Cutro AC, Hollmann A. Antimicrobial Action of Essential Oil of Tagetes minuta: Role of the Bacterial Membrane in the Mechanism of Action.. Antibiotics (Basel). 2025. PMID 40723935. DOI 10.3390/antibiotics14070632. (abstract)
- Cepeda DF, Ascari J, de Oliveira MS, Antonioli G, Barcellos T, Anholeto LA, Nunes PH. Effect of Tagetes minuta essential oil on the central nervous system of unfed Rhipicephalus sanguineus sensu lato 'tropical lineage' ticks.. Exp Appl Acarol. 2023. PMID 37985606. DOI 10.1007/s10493-023-00867-3. (abstract)
- Grosu Dumitrescu C, Jijie AR, Manea HC, Moaca EA, Iftode A, Minda D, Chioibas R, Dehelean CA, Vlad CS. New Insights Concerning Phytophotodermatitis Induced by Phototoxic Plants.. Life (Basel). 2024. PMID 39202761. DOI 10.3390/life14081019. (abstract)
- Hausen BM, Helmke B. Butenylbithiophene, alpha-terthienyl and hydroxytremetone as contact allergens in cultivars of marigold (Tagetes sp.).. Contact Dermatitis. 1995. PMID 7493459. DOI 10.1111/j.1600-0536.1995.tb00444.x. (abstract)
- Hudson JB, Graham EA, Rossi R, Carpita A, Neri D, Towers GH. Biological activities of terthiophenes and polyynes from the Asteraceae.. Planta Med. 1993. PMID 8255937. DOI 10.1055/s-2006-959729. (abstract)
- Igwaran A, Iweriebor BC, Ofuzim Okoh S, Nwodo UU, Obi LC, Okoh AI. Chemical constituents, antibacterial and antioxidant properties of the essential oil flower of Tagetes minuta grown in Cala community Eastern Cape, South Africa.. BMC Complement Altern Med. 2017. PMID 28676058. DOI 10.1186/s12906-017-1861-6. (abstract)
- Khan P, Waheed A, Azeem M, Parveen A, Yameen MA, Iqbal J, Ali M, Wang S, Qayyum S, Noor A, Naqvi TA. Essential Oil from Tagetes minuta Has Antiquorum Sensing and Antibiofilm Potential against Pseudomonas aeruginosa Strain PAO1.. ACS Omega. 2023. PMID 37810677. DOI 10.1021/acsomega.3c03507. (abstract)
- Ključevšek T, Kreft S. Allergic Potential of Medicinal Plants From the Asteraceae Family.. Health Sci Rep. 2025. PMID 39995792. DOI 10.1002/hsr2.70398. (abstract)
- Lis-Balchin M. Possible health and safety problems in the use of novel plant essential oils and extracts in aromatherapy.. J R Soc Promot Health. 1999. PMID 10673845. DOI 10.1177/146642409911900407. (abstract)
- Luan S, Muhayimana S, Xu J, Zhang X, Xiao C, Huang Q. Photosensitization of Chinese hamster V79 cells to photoactivated alpha-terthienyl involving membrane damage and oxidative stress.. J Photochem Photobiol B. 2018. PMID 29957498. DOI 10.1016/j.jphotobiol.2018.06.012. (abstract)
- Marotti I, Marotti M, Piccaglia R, Nastri A, Grandi S, Dinelli G. Thiophene occurrence in different Tagetes species: agricultural biomasses as sources of biocidal substances.. J Sci Food Agric. 2010. PMID 20394003. DOI 10.1002/jsfa.3950. (abstract)
- Moreira DA, Bolzan KP, Mazzarino L, Veleirinho MB, Honorato LA, Schuch LFD, Pinheiro Machado Filho LC, Kuhnen S. Preparation, physicochemical characterisation, storage stability and in vitro disinfectant activity of Tagetes minuta (L.) essential oil-loaded polycaprolactone nanocapsules against mastitis pathogens.. J Dairy Res. 2026. PMID 42831442. DOI 10.1017/S002202992610257X. (abstract)
- Salehi B, Valussi M, Morais-Braga MFB, Carneiro JNP, Leal ALAB, Coutinho HDM, Vitalini S, Kregiel D, Antolak H, Sharifi-Rad M, Silva NCC, Yousaf Z, Martorell M, Iriti M, Carradori S, Sharifi-Rad J. Tagetes spp. Essential Oils and Other Extracts: Chemical Characterization and Biological Activity.. Molecules. 2018. PMID 30388858. DOI 10.3390/molecules23112847. (abstract)
- Scientific Committee On Consumer Safety, Coenraads PJ. Opinion of the Scientific Committee on Consumer Safety (SCCS) - Opinion on the fragrance ingredients Tagetes minuta and Tagetes patula extracts and essential oils (phototoxicity only) in cosmetic products.. Regul Toxicol Pharmacol. 2016. PMID 26721339. DOI 10.1016/j.yrtph.2015.11.006. (abstract)
- US Food and Drug Administration. US FDA: Aromatherapy (page read 2026-10-25). n/a. 2026. (full-text)
- Walker S (veterinary student extern, University of Minnesota). Pet Poison Helpline: Essential Oils (page read 2026-10-25). n/a. 2026. (full-text)
- n/a. Poison Control (National Capital Poison Center): Essential oils: Poisonous when misused (page read 2026-10-25). n/a. 2026. (full-text)
- n/a. GBIF Backbone Taxonomy: Tagetes minuta L. (match API read 2026-10-25). n/a. 2026. (full-text)
- n/a. GBIF Backbone Taxonomy: Tagetes patula L. (match API read 2026-10-25). n/a. 2026. (full-text)
- n/a. PubChem compound name lookups (read 2026-10-25). n/a. 2026. (full-text)