What Is Epazote?

Epazote is the pungent leaf of Dysphania ambrosioides (formerly Chenopodium ambrosioides), a strongly aromatic annual in the amaranth family (Amaranthaceae) native to Mexico and the tropics of Central and South America. It leads a double life: it is at once a staple culinary herb — the unmistakable flavouring in Mexican bean dishes and other Mesoamerican cooking — and one of the region’s oldest traditional deworming remedies, a reputation preserved in its English name “wormseed.” Both the leaf and its steam-distilled essential oil are used, and the gap between the two matters more here than for almost any other herb on this site.

For most people epazote reaches the plate, not the medicine cabinet, and in the small amounts used as a seasoning it is simply safe. Its medicinal identity is narrower: a traditional anthelmintic, taken as a short leaf-decoction course to expel intestinal roundworm. That reputation runs through early-twentieth-century Western pharmacy too, where the concentrated “oil of chenopodium” was a recognised — if hazardous — commercial dewormer before safer synthetics replaced it.

The evidence, though, is thin for a herb this widely used. Only two human anthelmintic studies exist: a small paediatric trial in which leaf juice roughly matched albendazole against Ascaris ^{1Reference 1López De Guimaraes D et al. · 2001RCTLópez De Guimaraes D, Neyra Llanos RS, Romero Acevedo JH (2001). [Ascariasis: comparison of the therapeutic efficacy between paico and albendazole in children from Huaraz]. — [randomised clinical trial]. Rev Gastroenterol Peru. https://pubmed.ncbi.nlm.nih.gov/11818981/View study →}, and an older field trial in which dried powder proved essentially inert ^{2Reference 2Kliks MM · 1985Studies on the traditional herbal anthelmintic Chenopodium ambrosioides L.: ethnopharmacological evaluation and clinical field trials. — [clinical field trial]View study →} — so ascariasis is the best-supported use, and preparation clearly matters. Everything else — antiprotozoal, antifungal, anti-inflammatory and repellent activity — remains preclinical. The active oil is also its hazard: it is dominated by ascaridole, a genuinely toxic monoterpene peroxide whose effective anthelmintic dose sits close to the poisonous one, and epazote is a uterine stimulant historically used as an abortifacient, so the concentrated oil should never be self-administered and medicinal doses are contraindicated in pregnancy (see Safety).

How Is Epazote Used?

Epazote’s everyday use is culinary: fresh or dried leaf goes into bean dishes and other Mexican and Central American cooking in small amounts, mostly for flavour rather than medicine — and at this scale it’s simply safe. Medicinally, the traditional preparation is a leaf decoction taken as a short vermifuge course rather than an ongoing tonic: roughly half a cup, on an empty stomach, for three to four days, often alongside a mild laxative to help clear dead worms, with the course sometimes repeated after about two weeks to catch newly hatched eggs ^{1Reference 1López De Guimaraes D et al. · 2001RCTLópez De Guimaraes D, Neyra Llanos RS, Romero Acevedo JH (2001). [Ascariasis: comparison of the therapeutic efficacy between paico and albendazole in children from Huaraz]. — [randomised clinical trial]. Rev Gastroenterol Peru. https://pubmed.ncbi.nlm.nih.gov/11818981/View study →}.

The concentrated essential oil (“oil of chenopodium”) is a different matter and is not a self-administered remedy. It’s the ascaridole-rich fraction that carries both epazote’s anthelmintic potency and its toxicity, the two are difficult to separate, and the effective anthelmintic dose sits close to the toxic one — see Safety for the specifics. In practice this means: fine as a seasoning, worth knowing about as a traditional remedy, but not something to dose with the essential oil at home.

Traditional Uses

Western Herbal Medicine

Epazote (as “wormseed” or Chenopodium/Dysphania ambrosioides) entered Western and eclectic herbal practice largely through contact with Latin American use, adopted as a vermifuge for roundworm and other intestinal parasites and, to a lesser extent, as a carminative, diaphoretic, and mild laxative. Its oil was manufactured commercially as “oil of chenopodium,” a recognised — if hazardous — anthelmintic in early twentieth-century Western pharmacy before safer synthetic dewormers replaced it.

Traditional Chinese Medicine

Epazote has no meaningful history in Traditional Chinese Medicine. It is a Mesoamerican plant that was not part of the classical Chinese materia medica, and no traditional TCM pattern, meridian, or formula tradition assigns it a role.

Ayurvedic Medicine

Likewise, epazote has no genuine place in Ayurvedic medicine. It is native to Mexico and Central/South America and was unknown to classical Ayurvedic texts; any modern mentions reflect later global cross-referencing rather than an indigenous Ayurvedic tradition.

Indications

• Intestinal roundworm (ascariasis) — epazote’s best-supported use, backed by one small paediatric RCT showing leaf juice roughly matching albendazole ^{1Reference 1López De Guimaraes D et al. · 2001RCTLópez De Guimaraes D, Neyra Llanos RS, Romero Acevedo JH (2001). [Ascariasis: comparison of the therapeutic efficacy between paico and albendazole in children from Huaraz]. — [randomised clinical trial]. Rev Gastroenterol Peru. https://pubmed.ncbi.nlm.nih.gov/11818981/View study →}, alongside long-standing traditional use; an older field trial found dried powder ineffective, so preparation matters ^{2Reference 2Kliks MM · 1985Studies on the traditional herbal anthelmintic Chenopodium ambrosioides L.: ethnopharmacological evaluation and clinical field trials. — [clinical field trial]View study →}.
• Other intestinal parasites (e.g. Hymenolepis tapeworm) — supported by the same clinical trial as a secondary finding ^{1Reference 1López De Guimaraes D et al. · 2001RCTLópez De Guimaraes D, Neyra Llanos RS, Romero Acevedo JH (2001). [Ascariasis: comparison of the therapeutic efficacy between paico and albendazole in children from Huaraz]. — [randomised clinical trial]. Rev Gastroenterol Peru. https://pubmed.ncbi.nlm.nih.gov/11818981/View study →}.
• Protozoal infection (leishmaniasis, Chagas disease, amoebiasis, malaria) — consistent activity across multiple animal models, driven by ascaridole, but entirely preclinical with no human trials ^{6,7,8,9,10,11Reference 6Monzote L et al. · 2014In vitroEssential oil from Chenopodium ambrosioides and main components: activity against Leishmania, their mitochondria and other microorganisms. — [in vitro]View study →Reference 7Monzote L et al. · 2014AnimalAntileishmanial activity of essential oil from Chenopodium ambrosioides and its main components against experimental cutaneous leishmaniasis in BALB/c mice. — [in vivo mouse model]View study →Reference 8Avila-Blanco ME et al. · 2014AnimalAmoebicidal Activity of Essential Oil of Dysphania ambrosioides (L.) Mosyakin & Clemants in an Amoebic Liver Abscess Hamster Model. — [in vivo hamster model]View study →Reference 9Pagotti MC et al. · 2021In vitroTrypanocidal Activity of Dysphania ambrosioides, Lippia alba, and Tetradenia riparia Essential Oils against Trypanosoma cruzi. — [in vitro and in vivo]View study →Reference 10Pollack Y et al. · 1990In vitroThe effect of ascaridole on the in vitro development of Plasmodium falciparum. — [in vitro]View study →Reference 11Cysne DN et al. · 2016AnimalAntimalarial potential of leaves of Chenopodium ambrosioides L. — [in vivo mouse model]View study →}.
• Fungal skin and vaginal infections — supported by animal models of candidiasis and dermatophytosis using the essential oil, not the culinary tea ^{12,13Reference 12Chekem MS et al. · 2010AnimalAntifungal Properties of Chenopodium ambrosioides Essential Oil Against Candida Species. — [in vivo rat model]View study →Reference 13Prasad CS et al. · 2010In vitroIn vitro and in vivo antifungal activity of essential oils of Cymbopogon martini and Chenopodium ambrosioides and their synergism against dermatophytes. — [in vivo guinea pig model]View study →}.
• Mild inflammatory and pain conditions (e.g. arthritis-type joint pain) — supported by rodent models of oedema, nociception, and osteoarthritis; no human data ^{16,17,18Reference 16TrivellatoGrassi L et al. · 2013AnimalFrom popular use to pharmacological validation: a study of the anti-inflammatory, anti-nociceptive and healing effects of Chenopodium ambrosioides extract. — [animal model]View study →Reference 17Calado GP et al. · 2015AnimalChenopodium ambrosioides LView study →Reference 18Pereira WS et al. · 2018AnimalAnti-arthritic properties of crude extract from Chenopodium ambrosioides L. leaves. — [in vivo mouse model]View study →}.
• Insect and pest repellency — well-replicated bench-scale repellency and larvicidal activity of the essential oil ^{30Reference 30Gillij YG et al. · 2008In vitroMosquito repellent activity of essential oils of aromatic plants growing in Argentina. — [in vitro laboratory assay]View study →}.

Not indicated as a general-purpose antibacterial, antidiabetic, or cardioprotective agent — the evidence for those uses is thin (single studies, weak MICs, or cell-line/ex-vivo work only).

Botany

Epazote is the aromatic goosefoot Dysphania ambrosioides, long catalogued under the synonym Chenopodium ambrosioides and still often sold that way. It is a rangy, upright herb of the Amaranthaceae, growing waist- to shoulder-high with many untidy side branches and slender, toothed lance-shaped leaves. The whole plant is stippled with tiny glands, so the smallest bruise releases a heavy, resinous, almost turpentine-like scent — the trait that identifies epazote before you ever see its inconspicuous green flower spikes.

For the herbalist and the cook alike, the leaf is the material of interest. Fresh or dried, it is the culinary herb folded into Mexican bean and corn dishes and the traditional anthelmintic (“wormseed”) remedy. That dual identity carries a built-in hazard: the concentrated leaf-and-seed essential oil is dominated by ascaridole, which is both the source of the historic worm-expelling action and genuinely toxic in quantity — which is why culinary use leans on a modest amount of leaf while the distilled oil is treated as dangerous (see Safety).

Distribution

Epazote is a plant of the tropical Americas — Mexico and Central and South America — where it has been used as food and medicine for centuries. It has since escaped cultivation into a cosmopolitan weed, naturalizing across warm regions of North America, Europe, Africa, Asia and Australia and persisting readily on disturbed and waste ground.

Growing Conditions

• Wants full sun — six or more hours of direct light a day.
• Thrives in warm conditions; treat as an annual where winters are cold, though it may overwinter and return as a short-lived perennial in mild climates.
• Tolerant of poor, disturbed soils and reseeds vigorously — give it room and expect volunteers.
• Fast and undemanding from seed; harvest young leaves for the kitchen before heavy flowering.
• Full cultivation detail lives on the companion farm-wiki grow guide for Dysphania ambrosioides (link to be added once that project’s public URL is confirmed).

Pharmacology & Research

Epazote has a substantial preclinical literature — well over a hundred indexed studies — but it sits almost entirely at the animal and in-vitro tier, with two human trials of note and a heavy skew toward its steam-distilled essential oil. The plant’s reputation rests on its anthelmintic use against intestinal worms, and here the human data are real but mixed: a randomised trial in children found leaf juice (“paico”) roughly as effective as albendazole against Ascaris ^{1Reference 1López De Guimaraes D et al. · 2001RCTLópez De Guimaraes D, Neyra Llanos RS, Romero Acevedo JH (2001). [Ascariasis: comparison of the therapeutic efficacy between paico and albendazole in children from Huaraz]. — [randomised clinical trial]. Rev Gastroenterol Peru. https://pubmed.ncbi.nlm.nih.gov/11818981/View study →}, while an older field study found dried, powdered plant essentially inert ^{2Reference 2Kliks MM · 1985Studies on the traditional herbal anthelmintic Chenopodium ambrosioides L.: ethnopharmacological evaluation and clinical field trials. — [clinical field trial]View study →}. The most active and consistent modern signals are antiprotozoal — against Leishmania, Trypanosoma cruzi, amoebae and Plasmodium, driven largely by the endoperoxide monoterpene ascaridole acting through an artemisinin-like mechanism ^{6,10Reference 6Monzote L et al. · 2014In vitroEssential oil from Chenopodium ambrosioides and main components: activity against Leishmania, their mitochondria and other microorganisms. — [in vitro]View study →Reference 10Pollack Y et al. · 1990In vitroThe effect of ascaridole on the in vitro development of Plasmodium falciparum. — [in vitro]View study →}. The dominant caveat throughout is chemotype and preparation: ascaridole content ranges from a few percent to over half the oil depending on population ^{39Reference 39Cavalli JF et al. · 2004Combined analysis of the essential oil of Chenopodium ambrosioides by GC, GC-MS and 13C-NMR spectroscopy: quantitative determination of ascaridole, a heat-sensitive compound. — [analytical chemistry]View study →}, the oil is heat-sensitive ^{39Reference 39Cavalli JF et al. · 2004Combined analysis of the essential oil of Chenopodium ambrosioides by GC, GC-MS and 13C-NMR spectroscopy: quantitative determination of ascaridole, a heat-sensitive compound. — [analytical chemistry]View study →}, and effects shown for the concentrated oil do not transfer to the weak culinary tea most people actually consume.

1. Anthelmintic

This is epazote’s defining use, and it is the one indication with human data. A randomised trial in 60 children in Huaraz, Peru compared leaf juice (“paico”, 1–2 ml/kg once daily for three days) against a single 400 mg dose of albendazole for Ascaris lumbricoides: qualitative cure was identical at 86.7%, and quantitative egg-burden reduction was comparable (59.5% paico vs 58.3% albendazole), with paico additionally clearing Hymenolepis ^{1Reference 1López De Guimaraes D et al. · 2001RCTLópez De Guimaraes D, Neyra Llanos RS, Romero Acevedo JH (2001). [Ascariasis: comparison of the therapeutic efficacy between paico and albendazole in children from Huaraz]. — [randomised clinical trial]. Rev Gastroenterol Peru. https://pubmed.ncbi.nlm.nih.gov/11818981/View study →}. Against that, a careful 1985 field study in Mayan farmers found that dried, powdered plant — even at very high doses — had no significant effect on adult Ascaris, Necator or Trichuris, suggesting the belief in efficacy may partly reflect passage of senescent worms ^{2Reference 2Kliks MM · 1985Studies on the traditional herbal anthelmintic Chenopodium ambrosioides L.: ethnopharmacological evaluation and clinical field trials. — [clinical field trial]View study →}. The active principle is the endoperoxide ascaridole ^{3Reference 3Okuyama E et al. · 1993Ascaridole as a pharmacologically active principle of “Paico,” a medicinal Peruvian plant. — [isolation study]View study →}, but notably a water-soluble, ascaridole-independent nematocide also contributes to infusion activity and is gentler on mammalian smooth muscle than the oil ^{4Reference 4MacDonald D et al. · 2004In vitroAscaridole-less infusions of Chenopodium ambrosioides contain a nematocide(s) that is(are) not toxic to mammalian smooth muscle. — [in vitro / animal]View study →}; extracts are also active against Toxocara canis larvae ^{5Reference 5Reis M et al. · 2010In vitroToxocara canis: potential activity of natural products against second-stage larvae in vitro and in vivo. — [in vitro and in vivo]View study →}. Preparation is decisive — fresh juice and decoctions carry the activity, dried powder much less so.

Gap: the only positive human trial is small, single-site and 25 years old; the effect is preparation-dependent, and the effective anthelmintic dose sits uncomfortably close to the toxic dose of ascaridole.

2. Antiprotozoal

The most consistent modern signal. The essential oil and ascaridole are active against Leishmania promastigotes and amastigotes in vitro, disrupting parasite mitochondrial membrane potential ^{6Reference 6Monzote L et al. · 2014In vitroEssential oil from Chenopodium ambrosioides and main components: activity against Leishmania, their mitochondria and other microorganisms. — [in vitro]View study →}, and — importantly — the whole oil prevented lesion development in L. amazonensis-infected mice by intralesional injection, outperforming the reference drug glucantime, whereas purified components alone were ineffective or lethal ^{7Reference 7Monzote L et al. · 2014AnimalAntileishmanial activity of essential oil from Chenopodium ambrosioides and its main components against experimental cutaneous leishmaniasis in BALB/c mice. — [in vivo mouse model]View study →}. Oral essential oil reversed Entamoeba histolytica liver abscess in a hamster model (IC50 0.7 mg/mL against trophozoites) ^{8Reference 8Avila-Blanco ME et al. · 2014AnimalAmoebicidal Activity of Essential Oil of Dysphania ambrosioides (L.) Mosyakin & Clemants in an Amoebic Liver Abscess Hamster Model. — [in vivo hamster model]View study →}, the oil was the most active of three tested against Trypanosoma cruzi in vitro and in vivo ^{9Reference 9Pagotti MC et al. · 2021In vitroTrypanocidal Activity of Dysphania ambrosioides, Lippia alba, and Tetradenia riparia Essential Oils against Trypanosoma cruzi. — [in vitro and in vivo]View study →}, and ascaridole is a potent inhibitor of Plasmodium falciparum whose activity depends on its peroxide bridge — an artemisinin-like endoperoxide mechanism ^{10Reference 10Pollack Y et al. · 1990In vitroThe effect of ascaridole on the in vitro development of Plasmodium falciparum. — [in vitro]View study →}; leaf extract also suppressed P. berghei in mice ^{11Reference 11Cysne DN et al. · 2016AnimalAntimalarial potential of leaves of Chenopodium ambrosioides L. — [in vivo mouse model]View study →}. Across these the whole oil often beats its isolated constituents, pointing to synergy.

Gap: entirely preclinical, dominated by the concentrated oil at doses far above culinary exposure, and no human antiprotozoal trials exist.

3. Antifungal

The essential oil is a broad, reproducible antifungal. It cleared induced vaginal candidiasis in a rat model ^{12Reference 12Chekem MS et al. · 2010AnimalAntifungal Properties of Chenopodium ambrosioides Essential Oil Against Candida Species. — [in vivo rat model]View study →}, and combined with Cymbopogon martini oil resolved dermatophyte ringworm in guinea pigs at concentrations well below standard antifungal drugs ^{13Reference 13Prasad CS et al. · 2010In vitroIn vitro and in vivo antifungal activity of essential oils of Cymbopogon martini and Chenopodium ambrosioides and their synergism against dermatophytes. — [in vivo guinea pig model]View study →}. It completely inhibited Aspergillus flavus growth and its aflatoxin B1 production at 100 µg/mL and protected stored wheat for a year ^{14Reference 14Kumar R et al. · 2007In vitroEvaluation of Chenopodium ambrosioides oil as a potential source of antifungal, antiaflatoxigenic and antioxidant activity. — [in vitro]View study →}, and inhibited eight post-harvest fungi at 0.3% ^{15Reference 15Jardim CM et al. · 2008In vitroComposition and antifungal activity of the essential oil of the Brazilian Chenopodium ambrosioides L. — [in vitro]View study →}. Activity tracks the monoterpene fraction — α-terpinene and p-cymene dominate these oils.

Gap: all data are for the essential oil in vitro or in agricultural/veterinary models; there is no human antifungal evidence and the tea is not a demonstrated antifungal.

4. Anti-inflammatory

A coherent body of rodent work supports anti-inflammatory and antinociceptive activity of the leaf extract. Ethanol extract (150–500 mg/kg) reduced formalin-, PGE2-, capsaicin- and bradykinin-induced nociception and carrageenan paw oedema, and accelerated wound healing ^{16Reference 16TrivellatoGrassi L et al. · 2013AnimalFrom popular use to pharmacological validation: a study of the anti-inflammatory, anti-nociceptive and healing effects of Chenopodium ambrosioides extract. — [animal model]View study →}. In monoiodoacetate-induced osteoarthritis in rats the hydroalcoholic extract cut synovial inflammation and pain, with molecular docking implicating ascaridole at the NMDA receptor ^{17Reference 17Calado GP et al. · 2015AnimalChenopodium ambrosioides LView study →}, and in collagen-induced arthritis in mice it lowered IL-6 and TNF-α and preserved bone density ^{18Reference 18Pereira WS et al. · 2018AnimalAnti-arthritic properties of crude extract from Chenopodium ambrosioides L. leaves. — [in vivo mouse model]View study →}. Two newly isolated oxygenated monoterpenes inhibited nitric-oxide production in LPS-stimulated macrophages ^{19Reference 19Ai NTV et al. · 2026In vitroTwo New Highly Oxygenated Monoterpenes From the Seeds of Dysphania ambrosioides and Their Inflammatory Activity In Vitro and In Silico. — [in vitro and in silico]View study →}, and ascaridole was long ago identified as the sedative/analgesic principle of “paico” ^{3Reference 3Okuyama E et al. · 1993Ascaridole as a pharmacologically active principle of “Paico,” a medicinal Peruvian plant. — [isolation study]View study →}.

Gap: consistent but exclusively preclinical; effective doses and extract types vary between studies and none has been tested in humans.

5. Insect repellent

Epazote’s use as a bug repellent is supported by a deep bench literature. The essential oil repels Aedes aegypti mosquitoes ^{30Reference 30Gillij YG et al. · 2008In vitroMosquito repellent activity of essential oils of aromatic plants growing in Argentina. — [in vitro laboratory assay]View study →} and appears repeatedly among the more potent plant oils in larvicidal and stored-product-pest screens; limonene and other monoterpenes are implicated in the repellent effect ^{30Reference 30Gillij YG et al. · 2008In vitroMosquito repellent activity of essential oils of aromatic plants growing in Argentina. — [in vitro laboratory assay]View study →}. Chenopodium-based botanicals are also documented as acaricides and insecticides at bench and greenhouse scale.

Gap: the evidence is laboratory and semi-field repellency/insecticidal testing of the oil, not human field trials against disease vectors; efficacy and duration lag synthetic standards like DEET.

6. Anticancer

Preclinical only, but with one in-vivo signal. Kaempferitrin, the major flavonoid glycoside of the ethanol extract, reduced tumour volume and mass in a human liver-cancer (SMMC-7721) mouse xenograft without hepatotoxicity, acting via apoptosis and immune stimulation ^{24Reference 24Su M et al. · 2023AnimalKaempferitrin, a major compound from ethanol extract of Chenopodium ambrosioides, exerts antitumour and hepatoprotective effects in the mice model of human liver cancer xenografts. — [in vivo mouse xenograft]View study →}. The essential oil induced caspase-dependent apoptosis and G0/G1 arrest in the same SMMC-7721 line, sparing normal liver cells ^{25Reference 25Wang YN et al. · 2016In vitroEssential Oil of Chenopodium ambrosioides Induced Caspase-Dependent Apoptosis in SMMC-7721 Cells. — [in vitro]View study →}, and seed extract suppressed migration and invasion of these cells in vitro ^{26Reference 26Huang J et al. · 2023In vitroPossible Mechanism of Dysphania ambrosioides (L.) Mosyakin & Clemants Seed Extract Suppresses the Migration and Invasion of Human Hepatocellular Carcinoma Cells SMMC-7721. — [in vitro]View study →}. Whole-leaf extract inhibited Ehrlich ascitic and solid tumours in mice ^{27Reference 27Nascimento FR et al. · 2006AnimalAscitic and solid Ehrlich tumor inhibition by Chenopodium ambrosioides L. treatment. — [in vivo mouse model]View study →}.

Gap: one isolated-compound xenograft plus cell-line and non-clinical tumour models; no human oncology data, and the essential oil’s own toxicity limits therapeutic translation.

7. Antioxidant

Antioxidant activity is well documented in vitro — leaf and oil extracts show concentration-dependent DPPH/radical scavenging and reducing power tied to phenolic and flavonoid content (quercetin, kaempferol, rutin) ^{29Reference 29Zohra T et al. · 2019In vitroExtraction optimization, total phenolic, flavonoid contents, HPLC-DAD analysis and diverse pharmacological evaluations of Dysphania ambrosioides (L.) Mosyakin & Clemants. — [in vitro]View study →}. The one in-vivo study fed C. ambrosioides extract to fish and reported enhanced splenocyte viability and antioxidant-enzyme activity ^{28Reference 28Reyes-Becerril M et al. · 2019In vitroAntioxidant, intestinal immune status and anti-inflammatory potential of Chenopodium ambrosioides L. in fish: In vitro and in vivo studies. — [in vitro and in vivo]View study →}. Oil composition, and therefore antioxidant capacity, shifts markedly with soil nutrients and chemotype ^{39,40Reference 39Cavalli JF et al. · 2004Combined analysis of the essential oil of Chenopodium ambrosioides by GC, GC-MS and 13C-NMR spectroscopy: quantitative determination of ascaridole, a heat-sensitive compound. — [analytical chemistry]View study →Reference 40Blacio S et al. · 2026In vitroImpact of Soil Nutrients on Chemical Composition and Antioxidant Activities of Dysphania ambrosioides Essential Oil in Southern Ecuador. — [analytical / in vitro]View study →}.

Gap: mostly cell-free assays plus a single fish model; no mammalian or human antioxidant-outcome data, and results are highly extract- and chemotype-dependent.

8. Antibacterial

Mixed and generally modest. Against Helicobacter pylori the plant showed a real in-vivo signal — 50–60% eradication in infected mice and dose-dependent bactericidal killing in vitro (MIC 16 mg/L) ^{20Reference 20Ye H et al. · 2015In vitroAnti-Helicobacter pylori activities of Chenopodium ambrosioides L. in vitro and in vivo. — [in vitro and in vivo]View study →}. But against common bacteria the essential oil is weak: MIC ≥1024 µg/mL against Staphylococcus aureus, where its interest is instead as a NorA efflux-pump modulator that can potentiate norfloxacin ^{21Reference 21de Morais Oliveira-Tintino CD et al. · 2018In vitroInhibition of the essential oil from Chenopodium ambrosioides L. and α-terpinene on the NorA efflux-pump of Staphylococcus aureus. — [in vitro]View study →}, and only weak activity (MIC 1000 µg/mL) against cariogenic streptococci — though the same oil was strongly schistosomicidal, killing adult Schistosoma mansoni worms ^{22Reference 22Soares MH et al. · 2017In vitroChemical Composition, Antibacterial, Schistosomicidal, and Cytotoxic Activities of the Essential Oil of Dysphania ambrosioides (L.) Mosyakin & Clemants (Chenopodiaceae). — [in vitro]View study →}. The oil is also molluscicidal and cercaricidal against schistosome snail vectors ^{23Reference 23Pereira LPLA et al. · 2022In vitroMolluscicidal and cercaricidal activities of the essential oil of Dysphania ambrosioides (L.) Mosyakin & Clemants: Implications for the control of schistosomiasis. — [in vitro]View study →}.

Gap: direct antibacterial potency is low apart from H. pylori; the more promising roles (efflux inhibition, antiparasitic) are not classical antibacterial action, and there is no human data.

9. Cardioprotective

A single 2026 study perfused isolated rat hearts (Langendorff) and reported that an aqueous leaf extract (10–40 µg/mL) reduced ischaemia/reperfusion myocardial injury, with supportive antioxidant and anticoagulant effects ^{31Reference 31Kadi M et al. · 2026AnimalCardioprotective Effects of Dysphania ambrosioides Leaves Against Ischemia/Reperfusion-Induced Myocardial Injury in Langendorff-Perfused Rat Heart. — [ex vivo animal model]View study →}.

Gap: one ex-vivo isolated-organ study with no replication, no whole-animal or human data, and no defined active constituent.

10. Antidiabetic

One study reported that ethyl-acetate and other fractions of C. ambrosioides inhibited the carbohydrate-digesting enzymes α-amylase and α-glucosidase in vitro, alongside analgesic activity in animals ^{32Reference 32Drioua S et al. · 2024In vitroChemical Composition and Analgesic and Antidiabetic Activity of Chenopodium ambrosioides L. — [in vitro and animal]View study →}.

Gap: in-vitro enzyme inhibition in a single study, no glycaemic outcomes in animals or humans, and no dose translation.

Mechanisms

The whole essential oil is frequently more active than its isolated constituents (e.g. antileishmanial and antiprotozoal work), indicating synergy rather than a single active molecule. A 2026 systematic review of ascaridole summarises its ROS-generating, artemisinin-like endoperoxide activity across antiparasitic, anticancer and anti-inflammatory models, and stresses how few studies have tested the purified compound ^{33Reference 33Abadia ACM · 2026Systematic reviewChemistry and biological properties of Ascaridole: A systematic review. — [systematic review]View study →}.

Clinical trials

Two human studies exist, both for the anthelmintic indication — a randomised comparison against albendazole in children ^{1Reference 1López De Guimaraes D et al. · 2001RCTLópez De Guimaraes D, Neyra Llanos RS, Romero Acevedo JH (2001). [Ascariasis: comparison of the therapeutic efficacy between paico and albendazole in children from Huaraz]. — [randomised clinical trial]. Rev Gastroenterol Peru. https://pubmed.ncbi.nlm.nih.gov/11818981/View study →} and an earlier ethnopharmacological field trial ^{2Reference 2Kliks MM · 1985Studies on the traditional herbal anthelmintic Chenopodium ambrosioides L.: ethnopharmacological evaluation and clinical field trials. — [clinical field trial]View study →}. No registered modern clinical trials were identified for any other indication; the rest of the evidence base is preclinical.

Last checked: July 2026.

Phytochemistry

The medicinal weight of epazote sits in its essential oil, a volatile fraction dominated by oxygenated and hydrocarbon monoterpenes. The signature active is ascaridole, an unusual monoterpene peroxide that drives the plant’s anthelmintic reputation and its toxicity; its heat-sensitive thermal isomer isoascaridole is consistently co-reported. Ascaridole’s abundance varies enormously between populations, with some chemotypes instead dominated by α-terpinene or p-cymene, and minor oxygenated actives such as carvacrol and the sesquiterpene caryophyllene oxide also appear. Beyond the oil, the leaves carry non-volatile flavonoids — chiefly glycosides of kaempferol and quercetin, including kaempferitrin, the major flavonol glycoside of the ethanol extract.

Constituent Summary

Figures below are share of the steam-distilled essential oil (% of total oil) and are highly variable by geography, chemotype, and the heat-sensitivity of ascaridole; the flavonoids are non-volatile leaf compounds (not oil constituents), so their oil share reads No Data. † marks ascaridole, the chemotype-defining marker whose level separates ascaridole-rich populations from α-terpinene-rich ones.

Dosage

There is no standardised or research-derived medicinal dose for epazote, and — uniquely among culinary herbs — its effective anthelmintic dose sits uncomfortably close to the toxic dose of ascaridole, so the therapeutic margin is narrow and preparation-dependent. The single controlled human study used fresh leaf juice, not the essential oil; the concentrated “oil of chenopodium” is dangerously toxic and should not be self-administered (see Safety).

The paico dose is a fresh-leaf-juice volume from one paediatric trial ^{1Reference 1López De Guimaraes D et al. · 2001RCTLópez De Guimaraes D, Neyra Llanos RS, Romero Acevedo JH (2001). [Ascariasis: comparison of the therapeutic efficacy between paico and albendazole in children from Huaraz]. — [randomised clinical trial]. Rev Gastroenterol Peru. https://pubmed.ncbi.nlm.nih.gov/11818981/View study →}; it is not a whole-herb weight and does not convert to a dried-herb dose, so no equivalent is given. It is reported here as trial context, never as a recommendation — and the effective anthelmintic dose approaches the toxic range of ascaridole.

Traditional Dosage

Traditional use centres on the whole leaf as a short vermifuge course, deliberately favouring the lower-oil leaf over the oil-rich seed, and taken for only a few days rather than chronically.

Safety & Pregnancy

Epazote is safe in the small quantities used as a culinary herb, but its medicinal preparations carry real, dose-dependent risk that scales with essential-oil (ascaridole) content — the concentrated oil of chenopodium is dangerously toxic and has caused fatal poisonings.

Full safety & interactions detail

Epazote is safe in the small quantities used as a culinary herb, but its medicinal preparations carry real, well-documented risk that scales with essential-oil (ascaridole) content. The concentrated oil of chenopodium is dangerously toxic: overdose causes nausea, vomiting, headache, tinnitus, hallucinations, convulsions, respiratory depression and coma, and fatal paediatric poisonings from repeated high-dose infusions given as antipyretics are on record ^{34,35Reference 34Elhaddadi H et al. · 2024Case reportA Fatal Case Report of Chenopodium ambrosioides L. (M’khinza) Intoxication. — [case report]View study →Reference 35Badinga LPCL et al. · 2018Case reportBadinga LPCL, et al. (2018). [M’khinza-related intoxication: about two observations]. — [case report]. Pan Afr Med J. https://pubmed.ncbi.nlm.nih.gov/30918546/View study →}. In animals, aqueous leaf extract produced mild dose-dependent hepatotoxicity (raised ALT/AST, hepatocyte vacuolation) at gram-per-kilogram doses ^{36Reference 36da Silva MG et al. · 2014AnimalAcute and sub-chronic toxicity of aqueous extracts of Chenopodium ambrosioides leaves in rats. — [animal toxicity study]View study →}, while a lower-dose subchronic study caused no deaths but altered organ weights and serum chemistry ^{37Reference 37Pereira WS et al. · 2010AnimalEvaluation of the subchronic toxicity of oral treatment with Chenopodium ambrosioides in mice. — [animal toxicity study]View study →}, and both infusion and decoction were genotoxic to human lymphocytes in vitro (chromosomal aberrations, increased sister-chromatid exchange) ^{38Reference 38Gadano A et al. · 2002In vitroIn vitro genotoxic evaluation of the medicinal plant Chenopodium ambrosioides L. — [in vitro genotoxicity]View study →}. Medicinal or essential-oil doses should not be given to infants or young children, and the ascaridole-rich oil should not be self-administered as an anthelmintic ^{34,35Reference 34Elhaddadi H et al. · 2024Case reportA Fatal Case Report of Chenopodium ambrosioides L. (M’khinza) Intoxication. — [case report]View study →Reference 35Badinga LPCL et al. · 2018Case reportBadinga LPCL, et al. (2018). [M’khinza-related intoxication: about two observations]. — [case report]. Pan Afr Med J. https://pubmed.ncbi.nlm.nih.gov/30918546/View study →}. Ascaridole content — and therefore toxicity — varies enormously by chemotype, and the compound is heat-sensitive, so the potency of any given sample is unpredictable ^{39Reference 39Cavalli JF et al. · 2004Combined analysis of the essential oil of Chenopodium ambrosioides by GC, GC-MS and 13C-NMR spectroscopy: quantitative determination of ascaridole, a heat-sensitive compound. — [analytical chemistry]View study →}.

Herb–drug interactions have not been evaluated in humans: no clinical CYP450 or pharmacokinetic interaction study exists for epazote. The one interaction signal is an in-vitro finding that the oil modulates the Staphylococcus aureus NorA efflux pump (potentiating norfloxacin) ^{21Reference 21de Morais Oliveira-Tintino CD et al. · 2018In vitroInhibition of the essential oil from Chenopodium ambrosioides L. and α-terpinene on the NorA efflux-pump of Staphylococcus aureus. — [in vitro]View study →} — antimicrobial synergy in a dish, not a demonstrated mammalian drug interaction. Absence of interaction data is a gap, not a reassurance.

References

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Original notes (from the old site — sort into the sections above)

Epazote Summary:

Epazote is a herb originating from Mexico and the tropical regions of Central and South America. It is a common culinary herb, especially in these areas. It is also used as medicine throughout this region. The most common traditional and modern use of this herb is to treat parasitic worms, which has led to one of its common names; wormseed. It is a powerful anti parasitic and is useful for a range of other parasites and amoebas as well. It is the leaves and seeds that are used for this purpose and the essential oil contained in these parts is suggested to be the main component responsible. The oil is often referred to as “oil of chenopodium” and is a popular worm remedy worldwide. This essential oil is powerful, and should be used carefully. It is highly effective at treating parasites, however it also has its own set of negative side effects and at an intake of 10mg (a very high dose), symptoms such as cardiac disturbances, vomiting, diarrhea, convulsions, respiratory disturbances, and possibly death may occur. These effects can be avoided by consuming the leaf rather than the seeds, which have a lower essential oil content. To use this herb, 150 ml (½ cup) of standard leaf decoction should be consumed on an empty stomach for 3-4 days in a row. It is usually combined with a mild laxative as well to flush out the dead parasites. In 2 weeks the process should be repeated to kill any eggs that have hatched.

It has a variety of other traditional uses including treatment for asthma, excessive mucous, chorea, traumatic bleeding, arthritis (topically) as a perfume (despite its skunky smell), as a laxative and natural bug repellant.

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Herbal Actions:

• Antiamoebic
• Antibacterial
• Anticancer
• Anti-parasite
• Antiulcer
• Diaphoretic
• Diuretic
• Galactagogue
• Laxitive
• Nervine
• Repels insects
• Sedative (mild)
• Stimulates digestion
• Vermifuge
• Vulnerary

Botanical Name:

Chenopodium ambrosioides

Family:

Part used:

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Dosage:

(Leaves)

Decoction:

125 ml (½ cup) daily

Indications:

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Common Names:

• Epazote

Traditional Uses:

Botanical Description:

Habitat Ecology, and Distribution:

Harvesting Collection, and Preparation:

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Constituents:

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Pharmacology and Medical Research:

Toxicity and Contraindications:

Cautions:

Traditional Chinese Medicine:

Synergy:

References:

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