Epazote

What is Epazote?

Epazote is a cooking herb that can poison people when used as a medicine. It grows in Mexico and Central America. The plant is Dysphania ambrosioides, once called Chenopodium ambrosioides.

Cooks add a few fresh leaves to black beans, soups and stews. In folk use, a leaf tea was also drunk to clear worms from the gut. English names include wormseed and Mexican tea.

The oil of the plant holds ascaridole, a compound that has killed people. Modern human evidence for any health use is essentially absent. Long traditional use is not proof that it works, and not proof that it is safe.

How does Epazote work?

Most of what epazote does, good or bad, comes from ascaridole in its oil.

In test tubes and in animals, ascaridole paralyses and kills gut worms. It appears to damage worm cells through a burst of oxygen-driven stress. Whether a leaf tea does this in people is not established.

The same action can harm human cells. In animal studies, large doses injure the liver, kidneys, nerves and the inner ear. Poisoning reports in people follow the same pattern.

Laboratory work also shows the oil slows some bacteria and fungi. That has never been tested as a treatment in people.

Cooks say epazote cuts the gas that beans cause. No human trial has tested that idea.

What forms does Epazote come in?

Fresh leaves and sprigs are the usual food form, sold in Latin American markets.

Dried leaf is sold loose for tea. Seeds are sold too, and they are far stronger than leaf.

Wormseed oil, also called chenopodium oil, is the pressed oil of the plant. It is a known poison and is no longer an approved medicine. Some sellers still list it online.

Capsules, tinctures and mixed "wormseed" blends turn up in herbal shops. Their strength is rarely stated and rarely checked.

You will also meet epazote simply as a kitchen herb. That use means a few leaves in a large pot of beans.

Where it comes from:

Epazote was used across Mexico and Central America long before Spanish contact. The Nahuatl name epazotl points to that deep history.

Healers gave leaf tea for worms, wind, cramps and fever. It was also used to bring on a late period, which is one reason it was feared in pregnancy.

From the 1800s, wormseed oil entered Western medicine as a worm treatment. It was listed in the United States Pharmacopeia and used in hookworm campaigns.

Doctors dropped it by the mid-1900s. Safer drugs had arrived, and the oil had killed patients, among them children.

What does Epazote help with?

• Intestinal worms: This was the main medical use, and it is the most dangerous one. Wormseed oil was given for hookworm and roundworm for over a century. Lab and animal studies show ascaridole kills worms and their larvae. Old human reports were uncontrolled, and poisoning was common. Safe, tested drugs now exist for worms. A doctor should guide any treatment.
• Gas and bloating from beans: This is the everyday kitchen claim, and it is the lowest-risk one. Cooks add a sprig of epazote to a pot of beans to cut wind. No human trial has tested it. The amount used in food is small, and millions eat it this way without trouble.
• Stomach cramps and colic: Tradition used weak leaf tea for griping pain and wind. There is no human trial behind this. In high amounts the herb causes stomach pain and vomiting itself. Babies and children were never a safe group for this use.
• Painful periods: Folk healers used epazote for cramps and for late periods. That second use points to a real risk in pregnancy. No trial supports either claim. Use for period problems is not something this page can back.
• Fever and colds: Leaf tea was a general home remedy for fever, coughs and chills. Evidence here is limited to tradition and to lab tests on germs. No human study shows it shortens an illness.
• Flavouring food: This is the use with the best record. Epazote gives a sharp, resinous taste to beans, soups and quesadillas. Food amounts are small and spread across a whole pot. That is very different from drinking strong tea or taking the oil.

What are the side effects of Epazote?

• Nausea and vomiting
• Stomach pain and diarrhoea
• Headache and dizziness
• Ringing in the ears or hearing loss
• Blurred vision
• Skin rash from handling the plant
• Liver injury, with yellow skin or eyes
• Kidney injury, with little or no urine
• Fits (seizures)
• Confusion, coma and death with the oil or large doses

Good to know:

Mild stomach upset is the common complaint with leaf tea.

Serious harm is tied to the oil, the seeds, and large or repeated doses. Children are hurt at much smaller amounts than adults.

Severe poisoning can come on within hours. Some of the damage, such as hearing loss, can be permanent.

Is Epazote legal where you live?

In the United States and Mexico, epazote leaf is sold freely as an ordinary food herb. Wormseed oil is no longer an approved medicine in the United States. Herbal capsules and tinctures are sold as supplements and are not checked for strength before sale.

Options to discuss with a clinician

Do not swap one worm treatment for another on your own. Talk to a doctor or pharmacist first.

If a stool test shows worms, a doctor can prescribe tested drugs such as albendazole or mebendazole. These are well studied and dosed by body weight.

For gas from beans, a pharmacist can suggest simethicone or a bean enzyme product. Soaking and rinsing beans well helps too.

For ongoing stomach pain or period pain, see a doctor rather than treating it yourself.