What is Tareh?

Tareh is the Persian name for leek, a mild plant in the onion family. Cooks use the long green leaves and pale stem in soups, stews, herb rice and egg dishes. Persian and Unani healers also used it as a warming food to help digestion and to loosen a chesty cough.

For almost everyone, tareh is food first. A cooked serving gives fibre, vitamin K, folate and the sulfur compounds that give the onion family its smell.

The evidence line is simple. Tareh has a long, clear record in Persian and Unani kitchens and clinics, but we could not find human trials of leek itself for any health use. Long traditional use is not proof that something works, and that gap applies to every claim on this page.

How does Tareh work?

No one has shown how tareh acts in the body in people, so this part is a best guess.

When you cut or chew leek, sulfur compounds form. In lab dishes these act as antioxidants (chemicals that shield cells from damage) and can make platelets (the cell bits that form clots) a little less sticky.

Leek is also high in water and fibre, which is the most likely reason it helps some people pass stool more easily. That is a food effect, not a drug effect.

What forms does Tareh come in?

Fresh tareh is the main form. Cooks chop the green leaves and white stem into soup, stew, herb rice and omelettes.

You can also buy it dried and crumbled, or frozen and chopped. Pressed leek juice, leek powder and capsules exist, but they are rare and not made to a set strength.

Raw crushed leek is sometimes put on the skin in folk practice. This can sting and redden the skin, so we do not suggest it.

Where it comes from:

Leek is one of the oldest grown vegetables. It was eaten in ancient Egypt, Greece and Persia, and Roman writers praised it for the voice and the chest.

Unani texts class leek as warm and dry. In that system it was used to stir appetite, move wind and thin thick phlegm (sticky mucus).

In Iran today tareh is a kitchen staple rather than a medicine, in dishes such as ash soup and kuku sabzi.

What does Tareh help with?

• Sluggish digestion and poor appetite: This is the main Unani use. Leek was given as a warm, savoury food to wake up appetite and move trapped wind. There are no human trials testing leek for this. Some people find the opposite happens, because the fibre in leek causes gas and bloating.
• Mild constipation: Any help here comes from leek being a watery, high-fibre vegetable, like most greens. It is not special among vegetables. No trial has tested leek on its own for constipation. If stools stay hard for more than two weeks, or you see blood, get checked.
• Chesty cough with thick phlegm: Old Persian, Greek and Unani sources used leek broth to loosen phlegm (sticky mucus) and ease the chest. Warm liquid alone may explain most of the comfort people feel. There is no human trial of leek for cough. Leek is not a treatment for chest infection, asthma or COPD (a long-term lung disease).
• General diet quality: Studies that follow large groups of people link diets rich in onion-family vegetables with better heart and gut health. These studies watch habits; they cannot prove that leek caused the result. Eating tareh as part of a mixed vegetable diet is a reasonable, low-risk choice. Treat it as food, not as therapy.

Which foods are rich in Tareh?

1. Fresh leek (tareh): the plant itself, used in soups and stews
2. Ash reshteh, the Persian noodle and herb soup: leek is a core herb in it
3. Kuku sabzi, the Persian herb omelette: often made with chopped leek
4. Potato and leek soup: a common Western dish built on the same plant
5. Elephant garlic: the same species, Allium ampeloprasum, with a milder garlic taste

Practical Tips:

Tareh is a food first, so the simplest way to use it is in cooking.

What are the side effects of Tareh?

• Gas and bloating
• Burping and onion-like breath or body smell
• Loose stools after large amounts
• Heartburn or reflux in people prone to it
• Stinging, redness or blistering when raw crushed leek is put on skin
• Rare allergic reaction with itching, rash, swelling or wheeze

Good to know:

Tareh is a common food and most people eat it with no trouble at all.

Gas and bloating are the usual complaints, and they come from fructans, a fibre that gut bacteria feed on. People with IBS (irritable bowel syndrome) notice this most.

Allergy to onion-family plants is uncommon but real. Stop eating it and get urgent help if your lips, tongue or throat swell or you struggle to breathe.

How much Tareh should you take?

• Recommended daily: There is no established medicinal dose for tareh, because the human studies that would set one do not exist. As food, a normal serving is about half a cup to one cup of cooked leek, a few times a week. Concentrated leek juice, powder and capsules have no tested dose, and we do not suggest them.
• Best time of day: Any time. Most people eat it with a main meal. If leek gives you gas, avoid a large portion late in the evening.
• With or without food: With food, as part of a meal. Cooking leek softens the fibre and usually makes it easier on the gut than raw leek.
• Time to effect: Any effect on stools usually shows within one to three days. Comfort from warm leek broth is felt while you drink it. Nothing here builds up over months.
• How long to take it: Food amounts can be part of your diet for life. If you are eating extra leek for a symptom such as constipation or a cough, give it about two weeks and then look honestly at whether anything changed. If nothing has, stop and talk to a doctor.