Mexican Tarragon

The Aztecs knew T. lucida as yauhtli, a remedy for fever, for promoting urine and for epilepsy ^{26Reference 26Salehi et al. · 2018ReviewTagetes spp. essential oils and other extracts: chemical characterization and biological activity — reviewView study →}. Its leaves flavoured chocolatl, the foaming cocoa drink of the Aztecs ^{31,32Reference 31Fern · 2026Tagetes lucida — habit, range, habitat, edible, medicinal and other uses — species databaseView study →Reference 32North Carolina Extension Gardener Plant Tagetes lucida — description, origin, plant traits and poison characteristics — species databaseView study →}.

Colonial writers, among them Bernardino de Sahagún, recorded it as a fragrant ingredient of tobacco mixtures. Residues of the plant have been found in small Maya ceramic flasks thought to have held tobacco mixtures ^{30Reference 30Zimmermann et al. · 2021Metabolomics-based analysis of miniature flask contents identifies tobacco mixture use among the ancient Maya — archaeological residue analysisView study →}.

In Mexico and Guatemala it is known for its part in ceremonies for the dead, which appear to have pre-Columbian roots ^{30Reference 30Zimmermann et al. · 2021Metabolomics-based analysis of miniature flask contents identifies tobacco mixture use among the ancient Maya — archaeological residue analysisView study →}. The dried plant is also burned as an incense and to repel insects ^{31Reference 31Fern · 2026Tagetes lucida — habit, range, habitat, edible, medicinal and other uses — species databaseView study →}.

In Mexico the aerial parts are taken as an infusion or a hydroalcoholic extract for anxiety, depression, irritability and sadness, and the herb is sometimes sold in place of St John’s wort ^{26Reference 26Salehi et al. · 2018ReviewTagetes spp. essential oils and other extracts: chemical characterization and biological activity — reviewView study →}. It is prescribed for nervios and susto, two culture-bound conditions of nervous unrest and fright ^{12,26Reference 12Pérez-Ortega et al. · 2016Tagetes lucida Cav.: ethnobotany, phytochemistry and pharmacology of its tranquilizing properties — animal studyView study →Reference 26Salehi et al. · 2018ReviewTagetes spp. essential oils and other extracts: chemical characterization and biological activity — reviewView study →}.

In Morelos, healers and market sellers in ten regions recommended it as an infusion and a tincture for these nervous conditions ^{12Reference 12Pérez-Ortega et al. · 2016Tagetes lucida Cav.: ethnobotany, phytochemistry and pharmacology of its tranquilizing properties — animal studyView study →}.

It is also a digestive remedy, taken for stomach ache, abdominal cramps, diarrhoea, “cold in the stomach” and empacho (indigestion), including in children ^{19,26Reference 19Ventura-Martínez et al. · 2020Study of antispasmodic and antidiarrheal activities of Tagetes lucida in experimental models — animal studyView study →Reference 26Salehi et al. · 2018ReviewTagetes spp. essential oils and other extracts: chemical characterization and biological activity — reviewView study →}. Under the name pericón it is used for rheumatic and inflammatory pain ^{6Reference 6Ángeles-López et al. · 2026AnimalAntinociceptive effect of Tagetes lucida in an arthritic gout-pain model in rats — animal studyView study →}, and it is used for high blood pressure ^{18Reference 18Estrada-Soto et al. · 2021Antihypertensive and vasorelaxant mode of action of the ethanol-soluble extract from Tagetes lucida Cav. aerial parts — animal studyView study →}.

Decoctions of the aerial parts are given for intestinal worms and protozoal infections, and the herb is used as a mouthwash for toothache and gum disease ^{26Reference 26Salehi et al. · 2018ReviewTagetes spp. essential oils and other extracts: chemical characterization and biological activity — reviewView study →}. Externally it has been applied to scorpion stings and used to remove ticks ^{31Reference 31Fern · 2026Tagetes lucida — habit, range, habitat, edible, medicinal and other uses — species databaseView study →}.

Huichol communities in western Mexico smoke the dried leaves and flowers, alone or mixed with the wild tobacco Nicotiana rustica. The marigold is said to reduce the harshness of the tobacco ^{30Reference 30Zimmermann et al. · 2021Metabolomics-based analysis of miniature flask contents identifies tobacco mixture use among the ancient Maya — archaeological residue analysisView study →}.

In the rat forced-swimming test, an aqueous extract given orally for 14 days at 10, 50 and 100 mg/kg reduced immobility and increased swimming, with fluoxetine as the comparison drug. The same doses did not change general motor activity or male sexual behaviour ^{1Reference 1Guadarrama-Cruz et al. · 2008Antidepressant-like effects of Tagetes lucida Cav. in the forced swimming test — animal studyView study →}.

A follow-up compared methanol, hexane, dichloromethane and aqueous extracts and found only the aqueous one active, at 50 mg/kg. The effect appeared after 7 days and was abolished by the serotonin-synthesis inhibitor PCPA. The extract caused no deaths or behavioural changes when given by mouth ^{2Reference 2Guadarrama-Cruz et al. · 2012AnimalAntidepressant-like effect of Tagetes lucida Cav. extract in rats: involvement of the serotonergic system — animal studyView study →}.

A third study found an effect at 100 and 200 mg/kg that was blocked by the 5-HT1A antagonist WAY-100635, the 5-HT2A antagonist ketanserin and PCPA, but not by noradrenergic blockers. The aqueous extract contained quercetin at 7.72 mg/g ^{3Reference 3Bonilla-Jaime et al. · 2015Antidepressant-like activity of Tagetes lucida Cav. is mediated by 5-HT1A and 5-HT2A receptors — animal studyView study →}.

The active preparation is the aqueous extract, the closest match to the traditional tea.

Gap: Every study is in rats, and no clinical trial has tested the antidepressant use.

Pain relief has been found in several pain models and with three different extract types.

An ethanol extract was active in the writhing test in mice and the formalin test in rats. The response involved opioid and 5-HT1A receptors, as shown by blocking with naloxone and WAY-100635. Fractionation isolated quercetagetin 7-O-glucoside and 6,7-dimethoxycoumarin as active constituents. The extract caused no stomach damage, and it prevented the stomach damage caused by ketorolac when the two were given together ^{4Reference 4González-Trujano et al. · 2019Identification of bioactive metabolites and inhibitory receptors in the antinociceptive activity of Tagetes lucida Cav. — animal studyView study →}.

A geranyl-acetate-rich essential oil was also antinociceptive. The effect was attributed partly to β-caryophyllene, acting through opioid, benzodiazepine and 5-HT1A receptors and nitric oxide ^{5Reference 5Hernandez-Leon et al. · 2020Role of β-caryophyllene in the antinociceptive and anti-inflammatory effects of Tagetes lucida Cav. essential oil — animal studyView study →}.

In a rat gout-pain model, an aqueous extract at 562 mg/kg gave sustained relief comparable to ketorolac. The coumarin umbelliferone was active on its own at 316 mg/kg ^{6Reference 6Ángeles-López et al. · 2026AnimalAntinociceptive effect of Tagetes lucida in an arthritic gout-pain model in rats — animal studyView study →}.

Gap: All models are acute rodent pain; there is no chronic-pain or human evidence, and the effective doses are high.

Anti-inflammatory activity follows the coumarin fraction. In the mouse TPA ear-oedema model, hexane and acetone extracts were active. Among five isolated coumarins, 7-isoprenyloxycoumarin gave the strongest inhibition (81.1%) and herniarin reduced oedema by 54.4%. The substituent at the C-7 position of the coumarin appeared decisive ^{7Reference 7Monterrosas-Brisson et al. · 2020Anti-inflammatory activity of coumarins isolated from Tagetes lucida Cav. — animal studyView study →}.

A later study identified fifteen coumarins, flavonoids and terpenes and ranked their anti-inflammatory effects, two of them showing a dose response ^{8Reference 8Pérez-Díaz et al. · 2022In vitroIsolation, chemical characterization, and anti-inflammatory activity of coumarins, flavonoids, and terpenes from Tagetes lucida — in vitro / animal studyView study →}.

In neuroinflammation models, coumarin-rich fractions lowered the pro-inflammatory cytokines IL-1β and TNF-α and raised the anti-inflammatory IL-4 and IL-10 ^{20,21Reference 20Santibáñez et al. · 2023Dose-effect determination of a neuroprotector fraction standardized in coumarins of Tagetes lucida and bioavailability — animal studyView study →Reference 21Castro-Martínez et al. · 2023Effects of five coumarins and standardized extracts from Tagetes lucida Cav. on motor impairment and neuroinflammation induced with cuprizone — animal studyView study →}.

Gap: Endpoints are topical oedema and cytokine panels in rodents; no human anti-inflammatory outcome has been measured.

The antioxidant findings are in vitro. A methanolic leaf extract and several of its phenolics, including a new quercetagetin glycoside, two new phenolic acids and 7-methoxycoumarin, showed significant DPPH radical scavenging compared with α-tocopherol ^{9Reference 9Aquino et al. · 2002In vitroAn extract of Tagetes lucida and its phenolic constituents as antioxidants — in vitro studyView study →}.

Infusions blending the herb with oak leaves were tested for inhibition of monoamine oxidase A. The oak leaves carried most of the activity ^{10Reference 10Álvarez et al. · 2023In vitroAnalysis of Antioxidant Constituents of Filtering Infusions from Oak (Quercus sideroxyla Bonpl. and Quercus eduardii Trel.) and Yerbaniz (Tagetes lucida (Sweet) Voss) as Monoamine Oxidase Inhibitors — in vitro studyView study →}.

The essential oil reduced hydrogen-peroxide-induced oxidative stress in liver and lung cells by 15.6–40.4%, and gave modest UV protection in vitro, with an SPF of 13–14 ^{11Reference 11Caballero-Gallardo et al. · 2022In vitroPhotoprotective agents from aromatic plants: antioxidant activity and cytotoxic potential of Tagetes lucida Cav. essential oil — in vitro studyView study →}.

No antioxidant effect has been measured in a living organism.

This study began with interviews of healers and market sellers in ten regions of Morelos, Mexico, who recommended the herb as an infusion and tincture for nervous culture-bound conditions. Polar extracts were then tested in mice in the open-field, exploration-cylinder, hole-board, plus-maze and barbiturate-sleep tests ^{12Reference 12Pérez-Ortega et al. · 2016Tagetes lucida Cav.: ethnobotany, phytochemistry and pharmacology of its tranquilizing properties — animal studyView study →}.

Anxiolytic and sedative-like effects were confirmed. They were blocked by the 5-HT1A antagonist WAY-100635 and the GABA/benzodiazepine antagonist flumazenil, implicating both receptor systems. The coumarin dimethylfraxetin was identified as one possible active compound ^{12Reference 12Pérez-Ortega et al. · 2016Tagetes lucida Cav.: ethnobotany, phytochemistry and pharmacology of its tranquilizing properties — animal studyView study →}.

Gap: A single study in mice, with no clinical anxiety endpoint.

Seven coumarins and three flavonoids isolated from the aerial parts were tested against a broad panel of bacteria and fungi. The coumarins were the most effective against Gram-negative bacteria, and the two dimethoxy coumarins strongly inhibited the fungi Trichophyton mentagrophytes and Rhizoctonia solani ^{13Reference 13Céspedes et al. · 2006In vitroAntifungal and antibacterial activities of Mexican tarragon (Tagetes lucida) — in vitro studyView study →}.

An essential oil dominated by methyleugenol (46.15%) and estragole (32.93%) was antibacterial against multidrug-resistant Staphylococcus aureus and Pseudomonas aeruginosa and reduced their resistance to several antibiotics ^{14Reference 14Torres-Martínez et al. · 2022In vitroTagetes lucida Cav. essential oil and its main compounds are antibacterial and modulate antibiotic resistance in multi-resistant bacteria — in vitro studyView study →}.

A 2026 study found that estragole from the oil acted synergistically with meropenem and tobramycin against multidrug- and extensively drug-resistant Gram-negative bacteria ^{16Reference 16Araque M · 2026In vitroAntibacterial activity of estragole from Ocimum tenuiflorum and Tagetes lucida and synergistic effect with meropenem and tobramycin against MDR-XDR Gram-negative bacteria — in vitro studyView study →}.

The oil is also antifungal ^{15Reference 15Bandeira Reidel et al. · 2018In vitroChemical composition and antifungal activity of essential oils from four Asteraceae plants — in vitro studyView study →}, and an ethyl-acetate extract combined with Artemisia cina killed the sheep nematode Haemonchus contortus in vitro, with a synergistic effect ^{17Reference 17Santiago-Figueroa et al. · 2024In vitroSynergistic interaction of Artemisia cina and Tagetes lucida extracts on Haemonchus contortus — in vitro studyView study →}.

Gap: All data are in vitro; there is no infection model in animals or people. The most active preparation is the estragole- and methyleugenol-rich oil.

A crude ethanolic extract of the aerial parts, given by stomach tube at 10 and 100 mg/kg, lowered systolic and diastolic blood pressure in spontaneously hypertensive rats without changing heart rate. It also relaxed noradrenaline-contracted aortic rings, partly through the endothelium, by activating the NO/cGMP pathway and blocking calcium channels ^{18Reference 18Estrada-Soto et al. · 2021Antihypertensive and vasorelaxant mode of action of the ethanol-soluble extract from Tagetes lucida Cav. aerial parts — animal studyView study →}.

The coumarins 6,7,8-trimethoxycoumarin, scoparone and 7-methoxycoumarin (herniarin) were identified as the main vasorelaxant constituents ^{18Reference 18Estrada-Soto et al. · 2021Antihypertensive and vasorelaxant mode of action of the ethanol-soluble extract from Tagetes lucida Cav. aerial parts — animal studyView study →}.

It is one lab, one extract and rats only.

An aqueous extract relaxed guinea-pig ileum pre-contracted with potassium chloride (83.7%) and acetylcholine (77.2%), but barely affected electrically stimulated contractions. It also reduced the response to calcium, serotonin and histamine ^{19Reference 19Ventura-Martínez et al. · 2020Study of antispasmodic and antidiarrheal activities of Tagetes lucida in experimental models — animal studyView study →}.

In the mouse charcoal-meal test, low doses halved gut transit, as loperamide did. The coumarins umbelliferone and herniarin reproduced the antispasmodic effect ^{19Reference 19Ventura-Martínez et al. · 2020Study of antispasmodic and antidiarrheal activities of Tagetes lucida in experimental models — animal studyView study →}.

It is a single study, with no human digestive data.

A coumarin-standardized fraction given by mouth at 5, 10 and 20 mg/kg reduced blood–brain-barrier leakage and rebalanced pro- and anti-inflammatory cytokines in an LPS neuroinflammation model. The 10 and 20 mg/kg doses acted longer and more strongly, and the coumarins’ blood and brain levels were measured ^{20Reference 20Santibáñez et al. · 2023Dose-effect determination of a neuroprotector fraction standardized in coumarins of Tagetes lucida and bioavailability — animal studyView study →}.

In a cuprizone demyelination model in mice, extracts and five isolated coumarins, including herniarin, dimethylfraxetin and scoparone, limited motor impairment, protected the blood–brain barrier and shifted brain cytokines toward an anti-inflammatory profile ^{21Reference 21Castro-Martínez et al. · 2023Effects of five coumarins and standardized extracts from Tagetes lucida Cav. on motor impairment and neuroinflammation induced with cuprizone — animal studyView study →}.

Gap: Two studies from related groups, in rodent models only.

An ethanol extract of T. lucida roots at 500 mg/kg was tested against carbon-tetrachloride liver injury in rats. It lowered AST, ALT, ALP, CYP2E1 and TNF-α, both when given before and after the toxin, and the authors report a good safety margin ^{22Reference 22El-Newary et al. · 2021AnimalHepatoprotective effects of Tagetes lucida root extract in carbon-tetrachloride-induced hepatotoxicity in rats — animal studyView study →}.

Gap: a single rat study using the root, while the leaf and flower are the parts normally used.

In mice, T. lucida extracts and the coumarins herniarin and dimethylfraxetin were tested against ketamine-induced psychosis-like behaviours: hyperlocomotion, stereotyped behaviour, and cognitive and social deficits. Several extracts and both coumarins blocked most of the ketamine effects and strengthened haloperidol-induced catalepsy, suggesting action on dopaminergic and glutamatergic systems ^{23Reference 23Porras-Dávila et al. · 2022Herniarin, dimethylfraxetin and extracts from Tagetes lucida in psychosis secondary to ketamine and its interaction with haloperidol — animal studyView study →}.

Gap: One exploratory rodent study. The interaction with haloperidol is relevant to anyone taking antipsychotic drugs.

In a sulforhodamine-B screen, both aqueous and ethanolic extracts were cytotoxic to T47D breast cancer cells (ED₅₀ <20 µg/mL), but only the aqueous extract was cytotoxic to HeLa cervical cancer cells ^{24Reference 24Vega-Avila et al. · 2009In vitroCytotoxic activity of four Mexican medicinal plants — in vitro studyView study →}. The essential oil was only weakly antiproliferative against liver and lung cancer cells (IC₅₀ >250 µg/mL) ^{11Reference 11Caballero-Gallardo et al. · 2022In vitroPhotoprotective agents from aromatic plants: antioxidant activity and cytotoxic potential of Tagetes lucida Cav. essential oil — in vitro studyView study →}.

Gap: Cell-line work only, with no selectivity or animal tumour data.

Acute toxicity. An aqueous extract caused no significant toxic signs or deaths in mice at 2000 mg/kg ^{6Reference 6Ángeles-López et al. · 2026AnimalAntinociceptive effect of Tagetes lucida in an arthritic gout-pain model in rats — animal studyView study →}, and an oral aqueous extract caused no deaths or behavioural changes in rats ^{2Reference 2Guadarrama-Cruz et al. · 2012AnimalAntidepressant-like effect of Tagetes lucida Cav. extract in rats: involvement of the serotonergic system — animal studyView study →}.

Estragole and methyleugenol. The essential oil is mostly estragole, and some chemotypes are mostly methyleugenol ^{25,26Reference 25Cicció · 2004A source of almost pure methyl chavicol: volatile oil from the aerial parts of Tagetes lucida (Asteraceae) cultivated in Costa Rica — analytical studyView study →Reference 26Salehi et al. · 2018ReviewTagetes spp. essential oils and other extracts: chemical characterization and biological activity — reviewView study →}. After activation in the liver, both form DNA adducts and cause liver tumours in rodents at high doses ^{27,28,29Reference 27Schulte-Hubbert et al. · 2020In vitroEstragole: DNA adduct formation in primary rat hepatocytes and genotoxic potential in HepG2-CYP1A2 cells — in vitro studyView study →Reference 28Punt et al. · 2016Evaluation of interindividual human variation in bioactivation and DNA adduct formation of estragole — modeling studyView study →Reference 29Deshmukh et al. · 2023In vitroHuman translesion synthesis polymerases replicate across N2-dG methyleugenol and estragole DNA adducts — in vitro studyView study →}. A human model estimated that typical dietary estragole intake produces adduct levels below those linked to tumours in rodents ^{28Reference 28Punt et al. · 2016Evaluation of interindividual human variation in bioactivation and DNA adduct formation of estragole — modeling studyView study →}. The concern therefore rests on the essential oil and on heavy, prolonged medicinal use rather than on seasoning or an occasional cup of tea.

Skin. Contact with the sap on broken skin, followed by sunlight, can cause redness, burning pain and blisters, and the scent of the flowers can irritate the nose and eyes ^{32Reference 32North Carolina Extension Gardener Plant Tagetes lucida — description, origin, plant traits and poison characteristics — species databaseView study →}. The plant contains thiophene compounds ^{25,26Reference 25Cicció · 2004A source of almost pure methyl chavicol: volatile oil from the aerial parts of Tagetes lucida (Asteraceae) cultivated in Costa Rica — analytical studyView study →Reference 26Salehi et al. · 2018ReviewTagetes spp. essential oils and other extracts: chemical characterization and biological activity — reviewView study →}.

Drug interactions. In mice, several extracts and the coumarins herniarin and dimethylfraxetin strengthened haloperidol-induced catalepsy ^{23Reference 23Porras-Dávila et al. · 2022Herniarin, dimethylfraxetin and extracts from Tagetes lucida in psychosis secondary to ketamine and its interaction with haloperidol — animal studyView study →}. No human interaction studies have been done.

Allergy. As a member of the daisy family, it may cross-react in people allergic to other Asteraceae; this has not been tested.