What is Yi Tang?

Yi Tang is malt sugar. It is a thick, sweet syrup made by cooking grain, usually rice or sticky millet, with sprouted barley until the starch turns to sugar. In Chinese medicine it is used as a single herb, not just as a food.

It is given to warm and build up the middle of the body, meaning the stomach and gut. The classic use is cramping belly pain that eases with warmth and with gentle pressure. It is also used for weak digestion, low energy, and a dry, tickly cough.

Here is the honest picture. Yi Tang has a long, well recorded place in Chinese medicine, but almost no modern human trials test it on its own. Long traditional use is not proof that a remedy works, and we say that once here rather than in every section below.

How does Yi Tang work?

Most of what Yi Tang does is simple. It is mostly sugar, so it gives quick energy and tastes very sweet.

Your gut breaks maltose down into glucose, a simple sugar your body burns for fuel. That also raises blood sugar, which matters if you have diabetes.

In Chinese medicine, sweet and warm herbs are said to build the middle, that is, to support the stomach and gut, and to ease cramping. The sticky syrup coats a dry throat, which may be why it was used for dry coughs. These are traditional ideas, not proven drug actions.

No human study has shown that Yi Tang relaxes gut muscle, heals the gut lining, or calms a cough better than any other sweet syrup.

What forms does Yi Tang come in?

Soft malt syrup, called jiao yi, is the form used as a herb. It is thick, golden and very sticky.

A hard, dried version is also sold, often shaped into sweets.

In a herb formula it is stirred into the hot strained tea at the end. It is not boiled with the other herbs, because it scorches easily.

Food shops sell the same thing as barley malt syrup or rice malt syrup. That is the same sugar, but it is sold as a food and is not checked as a medicine.

Where it comes from:

Yi Tang appears in the Shang Han Lun, a Chinese medical text from about 200 CE. It is the lead herb in Xiao Jian Zhong Tang, a famous formula for cramping belly pain in people who tire easily.

Later Chinese herbals kept it in the tonic group, meaning herbs used to build strength after illness. It has stayed in steady use in China for roughly 1,800 years.

What does Yi Tang help with?

• Cramping belly pain that feels better with warmth: This is the main classical use, almost always inside the formula Xiao Jian Zhong Tang rather than alone. Practitioners pick it when pressing on the belly helps and a warm drink helps. We found no controlled human trial of Yi Tang by itself for belly pain.
• Weak digestion and poor appetite: Tradition treats it as a gentle food-like tonic for people who feel full quickly and tire after eating. Any real effect may simply be the easy calories it supplies. There is no trial evidence that it improves digestion.
• Tiredness while recovering from an illness: Sugar is fast fuel, so a sweet syrup can lift energy for a short while. That is not the same as treating the cause of tiredness. If you feel worn out for weeks, get the cause checked rather than treating it with syrup.
• Dry cough with a dry, scratchy throat: A thick sweet syrup coats the throat and can soothe it, much as honey or a cough sweet does. Trials of honey suggest sweet syrups help night cough in children a little, but those trials did not test Yi Tang. This use is traditional and, at best, comforting rather than curative.
• Dryness of the mouth and throat: Classical texts call Yi Tang moistening and use it for dryness. This is a taste and texture effect as much as anything. No human study supports it.

Which foods are rich in Yi Tang?

1. Barley malt syrup - the same malt sugar, sold as a food sweetener
2. Rice malt syrup - made the same way, from rice starch
3. Malt extract drinks and malted milk powders - built on the same sugar
4. Maltose candy and coated toffee fruits - the hardened form

Practical Tips:

Yi Tang is a food first and a herb second, so kitchen versions and herb-shop versions are very close in content.

What are the side effects of Yi Tang?

• Higher blood sugar after taking it
• Tooth decay with regular use, especially in children
• Bloating, wind or a full, heavy feeling in the belly
• Loose stools if you take a lot
• Nausea in people who already feel sick
• Weight gain if used daily for a long time
• A reaction in people who cannot tolerate barley, wheat or gluten

Good to know:

Yi Tang is food, so healthy adults taking a small amount for a short time rarely have trouble. The real problems come from what it is: a concentrated sugar.

The two effects that matter most are a rise in blood sugar and damage to teeth. Both build up quietly with daily use.

Chinese texts also warn against it when the belly feels swollen and full, or when there is a wet cough with thick phlegm, saying it makes those worse.

How much Yi Tang should you take?

• Recommended daily: No modern dose has been tested and proven. Chinese herbal practice commonly uses about 10 g to 30 g a day, stirred into warm water or into a strained herb tea. Classical formulas sometimes use more, up to about 60 g a day, under a practitioner's care.
• Best time of day: Usually once or twice a day, taken warm. Many practitioners give it before a meal or between meals for cramping pain.
• With or without food: Often taken between meals or shortly before food. It can be taken with food if it upsets your stomach on its own.
• Time to effect: Throat soothing is immediate but short lived, lasting minutes. Any effect on digestion or energy, if it comes at all, is judged over one to two weeks.
• How long to take it: Short courses only, usually one to two weeks. Reassess after two weeks. If your pain, cough or tiredness has not clearly improved, stop and see a health professional rather than carrying on.