What is Saishakurikkunshito?

Saishakurikkunshito is a Kampo herb formula from Japan. Doctors there use it for stomach upset and gut pain. It suits people who also feel tense or on edge.

The name means Bupleurum and Peony with Six Gentlemen Decoction. It is Rikkunshito plus two more herbs, saiko and shakuyaku. In Japan it is a Ministry-approved Kampo product, sold as Tsumura granules.

The evidence grade here is low. We could not find trials of this exact formula. Its base formula has more human data than it does.

Long use in Kampo is not proof that it works. That point is made once here, and not repeated below.

How does Saishakurikkunshito work?

How it works is not fully known. The herbs are thought to act in different ways.

In animal studies, Rikkunshito appears to raise ghrelin, a hunger hormone. It also appears to speed up how fast the stomach empties. Small human studies point the same way, but they do not settle it.

Saiko (bupleurum) holds saikosaponins. In lab tests these appear to calm inflammation (swelling in tissue). Whether that happens in people is not shown.

Shakuyaku (peony) holds paeoniflorin. In animal work it appears to ease cramping in the gut wall. Kampo theory says the two added herbs suit people who feel wound up.

What forms does Saishakurikkunshito come in?

Most people take it as dried extract granules. In Japan these are sold as a Ministry-approved Kampo product, such as Tsumura granules.

Tablets and capsules are also made. A traditional decoction (herbs boiled in water) is less common now.

Strength differs by maker. Do not swap brands without checking the dose on the label.

Where it comes from:

Kampo is the Japanese form of Chinese herbal medicine. Rikkunshito, the base of this formula, comes from a Chinese text of 1587.

Japanese doctors later added saiko and shakuyaku. The aim was to fit patients with stomach trouble who also felt tense.

Today it sits on the list of Ministry-approved Kampo formulas. Doctors in Japan can prescribe it under health insurance.

What does Saishakurikkunshito help with?

• Functional dyspepsia (stomach upset with no clear cause found): This is the main Kampo use. Small randomised trials of the base formula Rikkunshito suggest some help with fullness and upper gut pain. Trials of this exact formula are lacking, so the case rests mostly on Kampo practice.
• Poor appetite: Kampo doctors use it for weak appetite with a tired, tense state. In animal work Rikkunshito appears to raise a hunger hormone. Human proof for this formula is not available.
• Nausea and early fullness at meals: Hange and shokyo are classic Kampo herbs for nausea. Small studies of related formulas report less nausea. The effect size in people is not clear.
• Stress-linked stomach and gut pain: Saiko and shakuyaku were added for this pattern. Kampo texts describe tight sides, sighing and gut pain that worsens with worry. No trial tests this use directly.
• Acid reflux (stomach acid rising into the gullet): Some Japanese doctors add Rikkunshito-type formulas to acid-blocking drugs. Reported gains are modest and studies are small. Do not stop a prescribed acid drug to try this.
• Irritable bowel symptoms with tension: Traditional use only. Peony is used in Kampo for cramping pain. We found no human trial of this formula for bowel symptoms.

Which foods are rich in Saishakurikkunshito?

1. Licorice sweets: they add to the same glycyrrhizin load
2. Licorice or liquorice-root tea: the same problem
3. Very salty food: may add to fluid held in the body

Practical Tips:

Foods rich in potassium, such as bananas and greens, are sensible while you take it, unless your doctor says otherwise.

What are the side effects of Saishakurikkunshito?

• Puffy face, hands or legs from held fluid
• Quick weight gain over days
• Raised blood pressure
• Low potassium in the blood (hypokalaemia)
• Muscle weakness, cramps or aching
• Nausea or loose stools
• Rash or itch
• Rare liver injury, shown by dark urine or yellow skin
• Rare lung inflammation, shown by fever, dry cough and breathlessness

Good to know:

Most people tolerate it. The main bounded risk is the licorice (kanzo) in the blend.

Too much glycyrrhizin can cause pseudoaldosteronism (a salt and water problem that holds fluid, raises blood pressure and drops potassium). Low potassium can then cause muscle damage and weakness. It is more likely with higher doses, long use, and in older people.

These effects usually settle after stopping, but they need medical review. Liver and lung problems are rare and are linked to saiko-containing Kampo formulas. Report new fever, cough or yellow skin at once.

How much Saishakurikkunshito should you take?

• Recommended daily: In Japan the usual adult dose of extract granules is 7.5 g a day. It is split into two or three doses. Older or frail people often take less. No dose is set outside Japan. Follow the label or your prescriber. Do not raise the dose on your own, because the licorice risk rises with dose and time.
• Best time of day: Usually two or three times a day, spaced through the day.
• With or without food: Kampo practice is to take it before meals or between meals, with warm water. If it upsets your stomach, take it with food.
• Time to effect: Some people notice a change in one to two weeks. Judge it by four weeks.
• How long to take it: Review after two to four weeks. If nothing has changed by then, stop and get advice. Long runs need watching. If you take it for more than a few weeks, ask for blood pressure checks and a blood potassium test.