Epazote

Native peoples of the Americas have used infusions and decoctions of the leaves, roots and flowering tops for centuries to treat intestinal worms, and the leaves as a seasoning ^{2Reference 2Kliks MM · 1985Studies on the traditional herbal anthelmintic Chenopodium ambrosioides L.: ethnopharmacological evaluation and clinical field trials. — [clinical field trial]View study →}.

Among Mayan farmers in Chiapas, Mexico, decoctions of the plant were widely used and highly regarded for roundworm, at up to 300 mg of dried plant per kg of body weight ^{2Reference 2Kliks MM · 1985Studies on the traditional herbal anthelmintic Chenopodium ambrosioides L.: ethnopharmacological evaluation and clinical field trials. — [clinical field trial]View study →}.

Mexican traditional medicine also uses epazote as an emmenagogue and abortifacient, and to bring on or speed labour ^{44Reference 44Cabada-Aguirre P et al. · 2023ReviewMexican traditional medicines for women’s reproductive health. — [review]View study →}.

In Peru, paico is a traditional medicine regarded as nervine, antirheumatic and anthelmintic ^{3Reference 3Okuyama E et al. · 1993Ascaridole as a pharmacologically active principle of “Paico,” a medicinal Peruvian plant. — [isolation study]View study →}. The fresh leaf juice is given to children for roundworm ^{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 →}.

In Brazil the plant is erva-de-santa-maria or mastruço. It is taken as tea or infusion, or applied as a poultice, for inflammation, bruises and lung infections, and used against worms and fungal infections ^{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 →}. The leaves, called mastruz, are also taken for a range of other diseases ^{27Reference 27Nascimento FR et al. · 2006AnimalAscitic and solid Ehrlich tumor inhibition by Chenopodium ambrosioides L. treatment. — [in vivo mouse model]View study →}.

In Morocco the plant is m’khinza. It is given as an infusion and applied as a poultice to bring down fever, and used as an antiseptic, painkiller and antispasmodic ^{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 →}.

Epazote entered Western and eclectic herbal practice as “wormseed”, a vermifuge for roundworm and other intestinal parasites. It was also used as a carminative, diaphoretic and mild laxative.

Its distilled oil, “oil of chenopodium”, and the purified ascaridole were used with considerable success in mass deworming campaigns ^{2Reference 2Kliks MM · 1985Studies on the traditional herbal anthelmintic Chenopodium ambrosioides L.: ethnopharmacological evaluation and clinical field trials. — [clinical field trial]View study →}. Ascaridole also caused deaths, and the oil fell out of use ^{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 →}.

This is the one indication with human data. A randomised trial in 60 children aged 3–14 in Huaraz, Peru, compared paico leaf juice with albendazole for Ascaris lumbricoides. The juice was given at 1 ml/kg (under 10 kg) or 2 ml/kg, once before breakfast for three days, and albendazole as a single dose ^{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 →}.

Both cleared roundworm eggs from the stool in 86.7% of children, and cut the egg count by a similar amount (59.5% for paico, 58.3% for albendazole). Paico also cleared all cases of dwarf tapeworm (Hymenolepis nana). Side effects occurred in 23.3% of children in both groups ^{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 →}.

A 1985 field study among Mayan farmers in Chiapas, Mexico, found that dried, powdered plant, even at up to 6,000 mg/kg, had no significant effect on adult Ascaris, Necator or Trichuris, although the plant contained the expected amount of ascaridole. The author suggested the traditional belief may partly reflect the natural passage of dying worms, or that higher-ascaridole plants were used in the past ^{2Reference 2Kliks MM · 1985Studies on the traditional herbal anthelmintic Chenopodium ambrosioides L.: ethnopharmacological evaluation and clinical field trials. — [clinical field trial]View study →}.

Ascaridole is a potent anthelmintic. In laboratory tests on nematodes, however, almost 90% of the activity of the infusion came from a water-soluble compound other than ascaridole. Ascaridole reduced the contraction of rat gut muscle, while the infusion had no effect on it ^{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 killed Toxocara canis larvae in vitro, but did not reduce the larval burden in infected mice ^{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 →}.

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 close to the toxic dose of ascaridole.

The essential oil and ascaridole are active against both forms of Leishmania in vitro. They break down the parasite’s mitochondrial membrane potential, and the oil had the best selectivity ^{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 →}.

In mice infected with L. amazonensis, the whole oil injected into the lesions prevented them from developing and worked better than the reference drug glucantime. Its purified components had no effect, and a mixture of them killed the mice ^{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 cured amoebic liver abscess in hamsters at 8 and 80 mg/kg (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 →}.

Against Trypanosoma cruzi, the oil was the most active of three tested in vitro. In infected mice it cut parasite levels by only 6–12% ^{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 →}.

Ascaridole stopped the growth of Plasmodium falciparum at 0.05 µM, and its activity depends on its peroxide bridge, as artemisinin’s does ^{10Reference 10Pollack Y et al. · 1990In vitroThe effect of ascaridole on the in vitro development of Plasmodium falciparum. — [in vitro]View study →}. A leaf extract increased survival and lowered parasite levels in mice infected with P. berghei ^{11Reference 11Cysne DN et al. · 2016AnimalAntimalarial potential of leaves of Chenopodium ambrosioides L. — [in vivo mouse model]View study →}.

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

One essential oil, rich in α-terpinene and p-cymene, inhibited Candida at 0.25–2 mg/mL and cleared induced vaginal candidiasis in rodents within 12 days ^{12Reference 12Chekem MS et al. · 2010AnimalAntifungal Properties of Chenopodium ambrosioides Essential Oil Against Candida Species. — [in vivo rat model]View study →}.

Oils of epazote and Cymbopogon martini inhibited dermatophytes at 150–500 ppm, against 1,000–5,500 ppm for standard antifungal drugs. Ointments made from them cleared ringworm in guinea pigs in 7–21 days ^{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 →}.

Leaf oil completely inhibited Aspergillus flavus and its aflatoxin B1 production at 100 µg/mL, and protected stored wheat from fungi 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 →}. A Brazilian oil rich in ascaridole completely inhibited eight post-harvest fungi at 0.3%, and ascaridole was its main antifungal component ^{15Reference 15Jardim CM et al. · 2008In vitroComposition and antifungal activity of the essential oil of the Brazilian Chenopodium ambrosioides L. — [in vitro]View study →}.

One study found no activity against the fungi it tested ^{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 →}. All of this is the essential oil in vitro or in agricultural and animal models, with no human data.

Ethanol extract of the leaves and stems, at 150–500 mg/kg in rodents, reduced pain responses to formalin, PGE2, capsaicin and bradykinin, reduced carrageenan paw swelling, and sped 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 rats with chemically induced osteoarthritis, a hydroalcoholic leaf extract reduced knee swelling, synovial inflammation and pain. Molecular docking suggested ascaridole may act at the NMDA receptor ^{17Reference 17Calado GP et al. · 2015AnimalChenopodium ambrosioides LView study →}. In mice with collagen-induced arthritis, the extract 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 →}.

Monoterpenes isolated from the seeds, including two new ones, inhibited nitric-oxide production in 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 →}. Ascaridole was identified as the sedative and 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 →}.

All of this is preclinical, with extract types and doses that differ between studies.

The essential oil was one of 12 oils from Argentine aromatic plants tested against Aedes aegypti mosquitoes, most of which were repellent. Across the oils, limonene and camphor were judged the main repellent components ^{30Reference 30Gillij YG et al. · 2008In vitroMosquito repellent activity of essential oils of aromatic plants growing in Argentina. — [in vitro laboratory assay]View study →}.

The oil also killed Biomphalaria snails and schistosome larvae, although it was toxic to fish at similar concentrations ^{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 →}.

The evidence is laboratory testing of the oil, with no field trials against disease-carrying insects.

Kaempferitrin, the main flavonoid glycoside of the ethanol extract, reduced tumour volume and mass in mice carrying human liver-cancer (SMMC-7721) xenografts over 30 days. It induced tumour-cell death, stimulated B lymphocytes, and lowered liver enzymes rather than raising them ^{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 cell line, and was more toxic to the cancer cells than to 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 →}. A seed extract suppressed the 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 →}.

A leaf extract injected at 5 mg/kg inhibited Ehrlich ascitic and solid tumours in mice and increased survival, whether given before or after the tumour was implanted ^{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 tumor models; no human oncology data, and the essential oil’s own toxicity limits therapeutic translation.

Leaf extracts scavenge free radicals in vitro, in line with their phenolic and flavonoid content. HPLC found rutin, myricetin and quercetin, and a methanolic leaf extract had a DPPH IC50 of 130.7 µg/mL ^{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 →}.

In Pacific red snapper fed the extract for two to four weeks, spleen cells showed higher 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 with it antioxidant capacity, varies with soil and chemotype. Of three Ecuadorian oils, only one showed strong activity ^{40Reference 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 →}.

There is no mammalian or human antioxidant-outcome data.

Against Helicobacter pylori, the plant killed the bacteria in vitro (MIC 16 mg/L) and eradicated infection in 50–60% of infected mice, compared with 70% for standard triple therapy ^{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 →}.

Against Staphylococcus aureus the essential oil had little direct activity (MIC ≥1024 µg/mL). It did lower the MIC of norfloxacin by inhibiting the bacterium’s NorA efflux pump ^{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 →}. It had weak activity (MIC 1000 µg/mL) against tooth-decay bacteria, but killed all adult Schistosoma mansoni worms at 12.5–25 µg/mL ^{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 →}. It also killed schistosome larvae and the snails that carry them ^{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 →}.

Apart from H. pylori, direct antibacterial activity is low, and there is no human data.

A 2026 study perfused isolated rat hearts and found that an aqueous leaf extract (10–40 µg/mL) reduced injury from interrupted and restored blood flow. The extract also had 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 →}. It is a single study on isolated organs, with no whole-animal or human data.

One study found that ethyl-acetate and other fractions of the plant inhibited the carbohydrate-digesting enzymes α-amylase and α-glucosidase in vitro, alongside pain relief 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 →}. There are no blood-sugar results in animals or people.

Poisoning in children. In Morocco, a four-year-old girl was given four cups of m’khinza infusion and a whole-body poultice for a fever. Within four hours she had vomiting, diarrhoea and reduced consciousness, and she died in intensive care ^{34Reference 34Elhaddadi H et al. · 2024Case reportA Fatal Case Report of Chenopodium ambrosioides L. (M’khinza) Intoxication. — [case report]View study →}. A five-month-old infant and a ten-year-old girl died within 12 hours of drinking infusions given for fever ^{35Reference 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 →}. The Moroccan Poison Control Centre ranked the plant fourth among plant causes of death between 2009 and 2020 ^{34Reference 34Elhaddadi H et al. · 2024Case reportA Fatal Case Report of Chenopodium ambrosioides L. (M’khinza) Intoxication. — [case report]View study →}.

Essential oil. Ascaridole is a potent anthelmintic, but it caused human deaths, and the oil fell out of use as a dewormer ^{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 →}. The ascaridole content of the oil varies from a few percent to over half, so the strength of any sample is unpredictable ^{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 →}.

Liver and chromosomes. In rats, a single 3 g/kg dose of aqueous leaf extract raised liver enzymes, and 1 g/kg daily for 15 days raised ALT and creatinine and caused mild changes in liver cells ^{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 →}. In mice, a hydroalcoholic extract at up to 500 mg/kg for 15 days caused no deaths but changed some organ weights and blood measures ^{37Reference 37Pereira WS et al. · 2010AnimalEvaluation of the subchronic toxicity of oral treatment with Chenopodium ambrosioides in mice. — [animal toxicity study]View study →}. Infusion and decoction increased chromosome damage in human lymphocytes in vitro ^{38Reference 38Gadano A et al. · 2002In vitroIn vitro genotoxic evaluation of the medicinal plant Chenopodium ambrosioides L. — [in vitro genotoxicity]View study →}.

Interactions. No human drug-interaction or CYP450 study has been done. In the laboratory, the oil inhibited a bacterial efflux pump and boosted the effect of 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 →}.