What is Asthma weed?

Asthma weed is a small, hairy roadside weed of the spurge family. Its botanical name is Euphorbia hirta. The whole plant, cut above the root, is dried and brewed as a tea.

In Cuba and the Dominican Republic it is called yerba de la niña. In Trinidad and Tobago it is known as malomo. Caribbean healers used it for coughs, wheeze, loose stools and skin sores.

Long use in a tradition is not proof that a remedy works. It is not proof that it is safe either. Human trials of asthma weed are very few and very small, so treat its uses as unproven.

The fresh plant bleeds a milky sap when broken. That sap can sting skin and can injure the eye. Handle the fresh plant with care.

How does Asthma weed work?

No one has shown how asthma weed acts in the human body. Almost all of what is known comes from test tubes and from rats and mice.

In animal studies, extracts have relaxed airway muscle and reduced coughing. Other animal work points to a calming, sleep-like effect. These results have not been repeated in people.

In laboratory tests the plant slows the growth of some bacteria and gut parasites. Whether that happens inside a human gut is not known.

In cell studies, flavonoids from the plant dampen some inflammation signals. That is lab work. It does not show that the tea eases asthma or allergy in a person.

Animal studies also report more urine flow and lower blood sugar. Both effects are a reason for care, not a proven benefit. They may matter if you take water tablets or diabetes medicine.

What forms does Asthma weed come in?

Asthma weed is used most often as a tea made from the dried plant. In the Caribbean it is also picked fresh from the yard.

Forms you may meet: - Dried aerial parts, loose, for tea or a simmered decoction - Powder in capsules - Liquid extracts and tinctures in alcohol - Fresh juice or crushed leaf dabbed on skin - Dried leaf in some smoking blends

Strength is not standardised between brands or batches. A capsule and a cup of tea are not the same dose.

Smoking any plant matter irritates the airways. If you have asthma, smoke of any kind is a known trigger. The smoked form is the least sensible way to use this plant.

Where it comes from:

Caribbean folk healers have used asthma weed for well over a century. Island plant records describe it from the 1800s onward.

In Cuba and the Dominican Republic, yerba de la niña was brewed for children's coughs and diarrhoea. In Trinidad and Tobago, malomo was given for wheeze, worms and boils. The milky sap was dabbed on warts and corns.

The plant spread across the tropics with trade and travel. Similar uses are written down in West Africa, India and the Philippines. The English name came from its reputation for easing wheeze.

These records describe custom and belief. None of them were tests of whether the plant worked.

What does Asthma weed help with?

• Asthma and wheeze: This is the use the English name comes from. Caribbean healers gave the tea for tight, wheezy breathing. Animal studies show airway muscle relaxing. Good human trials are missing. Asthma can kill. Never use this plant in place of a reliever inhaler or a preventer inhaler.
• Cough and chest colds: The tea was a common home remedy for a dry, barking cough. Rodent studies report less coughing after extracts. There is no solid human trial. A warm drink of any kind soothes a throat, and that may be much of what people feel.
• Hay fever and blocked nose: Folk use extended to sneezing and itchy, runny noses. The flavonoids in the plant are often named as the reason. That link rests on cell studies of quercetin, not on trials of the herb. Treat the hay fever claim as untested.
• Diarrhoea and dysentery: This is one of the oldest uses across the Caribbean. The plant is rich in tannins, which bind and tighten gut tissue. Lab work shows activity against some gut bugs and amoebae. Human evidence is thin and old. Bloody stools, high fever or signs of water loss need a doctor, not a tea.
• Intestinal worms: Healers gave the tea to children for worms. Test tube studies show some effect on worms and parasites. Nothing shows it clears worms in a person. Proven worm medicines are cheap, safe and quick, so see a clinician.
• Boils, warts and skin sores: The milky sap was dabbed on warts and the crushed leaf on boils. The sap is an irritant, which may be why warts seemed to shrink. The same irritant can burn healthy skin and damage an eye. There is no trial support for this use.
• Urinary complaints: The tea was used to make people pass more water. Animal studies back a mild water-losing effect. No human trial shows benefit for any urinary illness. Burning, fever or back pain points to an infection that needs care.

What are the side effects of Asthma weed?

• Nausea and vomiting
• Stomach cramps
• Loose stools or, in some people, constipation
• Burning or tingling in the mouth and throat
• Drowsiness or dull-headedness
• Dizziness
• Rash, redness or blistering where the sap touches skin
• Pain, redness and blurred sight if sap reaches the eye
• Allergic reaction, including swelling and trouble breathing
• Passing more urine than usual

Good to know:

Mild gut upset is the usual complaint. Nausea, cramping and a bitter burn in the mouth are reported fairly often.

Two problems are serious. Sap in the eye can scar the surface and needs same-day care. A true allergy to spurge plants can cause swelling and breathing trouble.

The biggest risk is not the plant itself. It is using it instead of asthma treatment that works.

How much Asthma weed should you take?

• Recommended daily: There is no agreed safe or effective dose for asthma weed. No health body has set one. Labels on the dried herb often list about 1 to 2 grams for a cup of tea, up to three times a day. Capsule labels commonly sit in the 300 to 500 milligram range per capsule. These numbers reflect custom and marketing, not testing. This page describes what labels carry. It is not an instruction for you. Strength varies between batches, so the same spoonful is not the same dose twice.
• Best time of day: Timing does not appear to matter. There is no research on time of day for this plant. Some animal work suggests a calming, drowsy effect. If you feel sleepy after a dose, do not drive.
• With or without food: Taking it with food is the gentler option. The tannins in the plant can bite on an empty stomach. Food may blunt some of the effect, but nausea and cramping are the common complaints. If the tea upsets you, stop.
• Time to effect: Nobody can give you an honest number here, because the human studies that would set one do not exist. People who use the tea for a cough or loose stools usually report judging it within a day or two. It may do nothing at all. If your breathing or your gut is getting worse, stop and get medical help.
• How long to take it: Traditional use was short. People took it for a few days during an illness, not for months. No study has tested long-term use in people. Safety past a few weeks is simply unknown. If a symptom lasts more than a few days, that is a reason to see a clinician.