What is Shikunshito?

Shikunshito is a Japanese Kampo herbal formula of six herbs. It is used for weak digestion, poor appetite and low energy. Its old name is Four Gentlemen Decoction.

It is one of Japan's ministry-approved Kampo formulas, sold as Tsumura 75. Kampo practitioners give it to people who tire easily, eat little and feel bloated. It is treated as a gentle tonic blend, not as a treatment for one named disease.

Here is the honest verdict. Good human trials of this exact formula are very few. Its standing rests on long traditional use, and traditional use is not proof of effect.

One herb in it needs respect. Licorice can raise blood pressure and drop potassium, so this is not a blend to take casually or for months on end.

How does Shikunshito work?

Kampo theory holds that the formula warms and strengthens the spleen and stomach, which that tradition sees as the core of digestion.

In animal and cell studies, parts of the blend appear to speed stomach emptying and calm gut inflammation. Ginseng compounds have been shown in animals to act on appetite signals. Whether any of this happens in people taking the formula is not established.

One effect in humans is well known, and it is a risk rather than a benefit. Licorice contains glycyrrhizin, which blocks an enzyme called 11-beta-HSD2.

Blocking that enzyme can cause pseudoaldosteronism (a salt and water imbalance that acts like a hormone disorder). The body then holds on to salt and loses potassium. That can raise blood pressure and weaken muscles.

What forms does Shikunshito come in?

Most people take it as a granule packet, the standard form in Japan. Tsumura 75 is the ministry-approved extract granule.

You can also find tablets, capsules and loose herbs for a decoction (a tea made by boiling). The boiled decoction is the classical form.

Granules dissolve in hot water and are usually taken warm. Strength varies between brands, so read the label each time you switch products.

Where it comes from:

The recipe first appears in a Chinese text of 1078, the Taiping Huimin Heji Jufang, as Si Jun Zi Tang.

It became a base formula that many later recipes were built on. Japanese Kampo took it up and still uses it for the pattern it calls qi deficiency.

Japan's health ministry later approved it as a standard extract granule, listed as Tsumura 75. That approval covers manufacture and reimbursement, not proof of benefit in trials.

What does Shikunshito help with?

• Poor appetite: This is the classical use. Kampo doctors pick it for a pale, tired person who eats little. Animal work suggests some herbs in the blend act on appetite signals. Human trials of Shikunshito for appetite are few and small.
• Functional dyspepsia (upset stomach with no disease found): Kampo uses it for fullness, bloating and a heavy feeling after meals. Most clinical research in this family has studied a related formula, rikkunshito, not this one. So the evidence here does not carry over directly.
• Tiredness and low stamina: Traditional use targets low energy that comes with weak digestion, not tiredness from any cause. There is no good trial evidence that it lifts energy. Lasting tiredness needs a doctor's check for causes such as anaemia (low blood iron) or thyroid problems.
• Loose stools linked to weak digestion: Classical texts use it for soft, frequent stools in a person who is weak and cold. Human evidence is lacking. Do not self-treat diarrhoea that lasts more than a few days, or that has blood in it.
• Slow recovery after illness or surgery: Kampo practice uses it as a short tonic course while strength returns. This use is traditional. No reliable human trials show faster recovery, and licorice makes long courses unwise without monitoring.

Which foods are rich in Shikunshito?

1. Fresh ginger: one of the six herbs, and a common kitchen spice
2. Jujube (Chinese date): eaten as a dried fruit as well as used as a herb here
3. Licorice sweets and licorice tea: they hold the same compound that raises blood pressure risk

Practical Tips:

Count licorice sweets and licorice tea as part of your total licorice intake while taking this formula.

What are the side effects of Shikunshito?

• Puffy face, ankles or hands from fluid build-up
• Rising blood pressure
• Low potassium, which can cause muscle weakness and cramps
• Muscle pain or weakness (myopathy, muscle damage) with long use
• Irregular or thumping heartbeat
• Nausea or loose stools
• Skin rash or itching
• Trouble sleeping or feeling jittery, linked to ginseng
• Lower blood sugar, which matters if you treat diabetes
• Rarely, signs of liver trouble such as yellow eyes or dark urine

Good to know:

Most people who take a short course have no trouble. The formula is mild by design.

The licorice problems are the ones to watch. They build up with dose and time, and they are more likely in older people and in anyone on water pills.

Stop taking it and get medical advice if you swell up, feel weak, or your heartbeat feels odd. These are not effects to wait out.

How much Shikunshito should you take?

• Recommended daily: The usual adult dose of the Japanese extract granule is 7.5 g a day. It is split into two or three doses. Children get less, based on age and weight, and only with a practitioner's advice. Other brands and tablets differ, so follow the label. Do not take it alongside another licorice-containing formula or licorice sweets. The licorice load adds up.
• Best time of day: Kampo practice is to take it before meals or between meals, spread through the day.
• With or without food: Take it on an empty stomach, about 30 minutes before a meal. If that upsets you, take it with a little food.
• Time to effect: Some people notice easier digestion within one to two weeks. Nothing is promised, and a lack of change by four weeks is a reason to stop.
• How long to take it: Short courses are safer. Review how you feel after two to four weeks. If nothing has changed by then, stop and get advice instead of pushing on. Long or repeat use needs your blood pressure and potassium checked by a doctor.