What is Dan Zhu Ye?

Dan Zhu Ye is a Chinese herb. It is made from the stem and leaves of a grass called Lophatherum gracile. It is a single drug (one herb on its own, not a blend), and it is also sold as Lophatherum stem and leaves.

People drink it as a tea for what Chinese medicine calls heat signs. That means a hot, restless feeling, thirst, mouth or tongue sores, and dark urine that stings. It is also used to help the body pass more urine.

Here is the plain verdict on the evidence. We found no human trials of this herb on its own, so no one can say it treats any illness. Long use in a tradition is not proof that a herb works.

How does Dan Zhu Ye work?

No one has shown how Dan Zhu Ye works in the human body.

Lab tests find plant chemicals in the leaves that can calm swelling and slow the growth of some germs in a dish. Animal tests suggest it may raise urine output. A dish or a mouse is not a person, so these results may not carry over to you.

In Chinese medicine the idea is that the herb pulls heat away from the heart and stomach and sends it out in the urine. That is a traditional idea, not a lab finding.

What forms does Dan Zhu Ye come in?

Dan Zhu Ye is sold as:

Dried cut stem and leaf, boiled into a tea (a decoction). This is the usual form.

Granules or powder that you stir into hot water.

An item inside classic Chinese formulas, such as Dao Chi San.

Tinctures and capsules are uncommon. Quality varies a lot between sellers, and some products are mixed up with bamboo leaf.

Where it comes from:

Dan Zhu Ye has been used in China for many hundreds of years. It was written up in the great Ming dynasty herb book Ben Cao Gang Mu in 1578.

It is a normal, everyday herb in Chinese practice, used mainly in summer teas and in mixes for fever and mouth sores. It is not the same plant as Zhu Ye, which is true bamboo leaf, although the two are often swapped by mistake.

What does Dan Zhu Ye help with?

• Mouth and tongue sores: This is one of the best known traditional uses. Chinese practitioners add Dan Zhu Ye to mixes for sore, red patches in the mouth. No human trial has tested it for this, so we cannot say whether it helps.
• Feeling hot, restless and thirsty: Classic texts describe this as the herb's main job. It is drunk as a cooling summer tea. The support here is tradition and personal reports only, not trial data.
• Dark, scanty or stinging urine: Tradition uses it to make urine flow more freely. Animal work hints at more urine output. Stinging urine can be a bladder infection, which needs a doctor, not a tea.
• Lingering low fever after an illness: It appears in old formulas for people still feeling hot and dry as they recover. There is no trial evidence for this use. A fever that will not settle needs medical review.
• Trouble sleeping from feeling hot and edgy: Chinese medicine links restless sleep to heart heat and uses this herb as part of a mix. No sleep trials have been done on it.

Which foods are rich in Dan Zhu Ye?

1. Chinese cooling summer teas: Dan Zhu Ye is a common ingredient
2. Herbal 'liang cha' drinks sold in southern China: often include the leaf

Practical Tips:

It is a medicinal herb, not a food, and is not found in an ordinary diet.

What are the side effects of Dan Zhu Ye?

• Passing more urine than usual, including at night
• Mild stomach upset or loose stools
• Feeling cold, weak or tired with long or heavy use
• Dizziness or dry mouth from losing too much fluid
• Rash or itching in people allergic to grasses (uncommon)

Good to know:

Most people who drink this as a tea for a few days have no trouble. The most common effect is simply passing more urine.

Problems are more likely with large amounts, long use, or in people who are frail, elderly, or already on water pills.

How much Dan Zhu Ye should you take?

• Recommended daily: No dose has been set by research, because the trials have not been done. Chinese practice most often uses 6 to 9 grams of the dried herb per day, boiled into a tea. Some texts go up to 15 grams per day for short spells. If you buy granules or powder, follow the label, as strengths differ a lot. A trained practitioner should set the dose for children, older people, or anyone with a long-term illness.
• Best time of day: Usually in the daytime, split into two or three warm drinks. Avoid the last dose close to bedtime, since the herb can send you to the toilet at night.
• With or without food: It is normally drunk warm between meals. If it upsets your stomach, take it with food. Drink normal amounts of water while you use it.
• Time to effect: People who use it for a hot, restless feeling often report a change within a day or two. More urine may follow the first few doses. None of this has been measured in a trial.
• How long to take it: Short use only. Tradition treats it as a herb for days, not months. A few days up to about two weeks is typical. Stop and see a doctor if your problem has not eased within a week. Do not keep taking it week after week to feel better. Long use can leave you passing too much fluid and feeling cold, weak or dizzy.