What is Yongchi?

Yongchi is dragon tooth. It is a fossil tooth from an animal that died long ago, dug out of rock. Healers wash it, grind it to a fine powder, and use it as a calming medicine.

It is a single drug used in Korean medicine, not a blend. Its Latin name is Dens Draconis. In English it is called dragon tooth, and in Chinese practice it is called long chi.

Old texts give it to settle the mind. They use it for a racing heart, fear, bad dreams and broken sleep. Some also use it for fits (sudden shaking caused by a burst of activity in the brain).

The evidence is weak. No human trial has tested Yongchi. It has a long record of use in East Asia, but long use is not proof that a thing works.

How does Yongchi work?

No one has shown how Yongchi works in the body. Most of it is calcium in mineral form, the same kind of material found in bone and chalk.

In the stomach, calcium can soak up acid, much like a plain antacid (a stomach acid tablet). That may ease some stomach upset. It does not explain calm or better sleep.

Korean and Chinese theory says Yongchi is heavy, so it "anchors" a restless spirit and draws rising energy back down. That is a traditional idea. It has not been tested in people.

The mineral is hard and does not dissolve well. Much of what you swallow may pass straight through you.

What forms does Yongchi come in?

Yongchi is sold and used in a few simple forms.

Raw powder: the washed fossil ground fine. Calcined powder: the fossil baked in high heat first, then ground, which makes it easier to crush. Broken chips: added to a decoction (a water brew simmered on the stove), usually started before the softer herbs.

It also turns up inside ready-made Korean and Chinese pills and granules for sleep and worry. It is rarely sold on its own in Western shops.

Where it comes from:

Dragon bone and dragon tooth appear in the oldest Chinese herb classic, the Shennong Bencao Jing, written around 2,000 years ago. The "dragons" were fossil animals, though early writers did not know that.

Korean medicine took the drug up and kept it. It appears in the Dongui Bogam, the great Korean medical text of 1613, in formulas for fright, panic and poor sleep.

It is still used today in Korea, China and Japan, mainly inside mixed formulas rather than alone.

What does Yongchi help with?

• Trouble sleeping (insomnia): This is the most common use. Korean and Chinese formulas add Yongchi to help a person who lies awake with a busy mind. No human trial has tested it for sleep, alone or in a formula.
• Palpitations (a pounding or racing heart): Old texts use it when the heart feels like it is thumping from fear or stress. There is no trial evidence. A pounding heart can have serious causes, so get it checked before treating it yourself.
• Anxiety, worry and fright: Traditional writers describe Yongchi as heavy and settling, and give it after a shock or during long-running worry. No study has measured anxiety scores in people taking it.
• Bad dreams and night terrors: A classic use, often in children. It rests on centuries of practice only. We found no laboratory or human work on dreams.
• Restlessness and irritability: Used when a person feels wound up and cannot sit still. This is a traditional reading of the drug, not a tested effect.
• Fits in children (traditional use): Historic texts list dragon tooth for convulsions (fits). Do not treat fits at home. Fits need a doctor, and modern seizure care works and is well tested.

Which foods are rich in Yongchi?

Yongchi is a fossil mineral. It is not found in any food.

What are the side effects of Yongchi?

• Constipation
• Bloating and wind
• Upset stomach or nausea
• A chalky, gritty taste
• Poor appetite
• Too much calcium in the blood, with thirst, weakness and confusion (rare)
• Build-up of lead or other heavy metals with long use

Good to know:

Most reported problems are mild and involve the gut, and they stop when you stop the powder.

The bigger worry is not a side effect you feel. It is the slow build-up of heavy metals from a mineral dug out of the ground. That is why long use is a bad idea and why lab-tested stock matters.

If you feel very thirsty, weak, sick or confused while taking it, stop and see a doctor.

How much Yongchi should you take?

• Recommended daily: No safe or effective dose has been set by modern research. What follows is traditional practice, not a tested amount. Practitioners commonly simmer 9 to 15 grams of the chips in a decoction. Ground powder is used in much smaller amounts, around 1 to 3 grams a day. Use it only under a trained Korean medicine practitioner who can source lab-tested material.
• Best time of day: Traditionally taken in the evening, and often an hour or two before bed, because it is used for sleep and calm. Keep it at least two hours apart from any medicine you take by mouth.
• With or without food: Usually taken between meals with warm water. The calcium in it can block iron and other minerals in food, so do not take it with an iron-rich meal or an iron pill.
• Time to effect: Unknown. No trial has measured it. Traditional practice expects some change in sleep or restlessness within one to two weeks.
• How long to take it: Traditional use is short-term, usually a few weeks at a time. Stop and reassess after two to four weeks. Do not take it month after month. A fossil mineral can carry lead and other heavy metals, and those build up in the body over time.