What is Senkinnaitakusan?

Senkinnaitakusan is a Kampo herbal formula from Japan. Its name means Thousand Ducat Powder for Internal Support of Sores. It is used for boils and sores that drain slowly and heal badly.

It is one of Japan's ministry-approved Kampo formulas. Doctors there prescribe it as dried extract granules, made by Tsumura and other firms. Tradition matches it to a person who is tired, pale and run down.

The proof in people is thin. We found no published human trials of this formula. Long use inside a tradition is not the same as proof that it works, and that holds here.

How does Senkinnaitakusan work?

In Kampo theory, the formula builds the body up so it can clear a sore from the inside. It is called a tonifying formula, meaning it aims to restore strength rather than attack a germ.

Several of its herbs have been studied alone. In lab and animal work, ogi (astragalus) and ninjin (ginseng) extracts appear to shift the activity of immune cells. Kikyo (balloon flower root) saponins loosen mucus in animal tests.

Whether any of this happens in a person who takes the whole mix is not known. No study has traced how the blend acts in the body. Treat the mechanism as an idea, not a finding.

What forms does Senkinnaitakusan come in?

In Japan it is mostly a dry extract granule. It comes in single-dose sachets and is taken with warm water. This is the form a doctor prescribes.

Some Kampo clinics still boil the raw herbs into a tea. Powders and capsules exist but are less common.

Outside Japan, supply is limited. Product quality and herb amounts vary, so check the label and the maker.

Where it comes from:

The name points to the Qianjin, or Thousand Ducat, line of Chinese formula books. Recipes of this kind were written down in China and later carried into Japan.

Japanese Kampo doctors took it up for sores that would not close. It has been used there for centuries and is still listed today. Its standing is strongest in Kampo and it is little known elsewhere.

What does Senkinnaitakusan help with?

• Boils and abscesses that drain slowly: This is the classic Kampo use. The formula is given when a boil is soft, dull and slow to clear, in a person with low strength. There are no published human trials to test that use.
• Skin sores and ulcers that heal poorly: Kampo doctors use it for sores that stay open for weeks. The aim is to support the body, not to kill germs. Evidence here is tradition and case notes only, not trial data.
• Repeat skin infections in people who are run down: Tradition points to people who are pale, tired and quick to catch infections. No trial has tested whether the formula cuts how often infections come back. Repeat abscesses need a medical check for causes such as diabetes.
• Wounds that stay open after surgery or injury: Some Japanese practitioners use it after surgery when a wound is slow to close. This use rests on tradition. A wound that will not close should be seen by a doctor or wound nurse.
• Tiredness alongside a long-running sore: The formula holds tonifying herbs such as ginseng and astragalus. In Kampo, these are given for low energy that goes with a long illness. We found no human trials of this effect for this formula.

Which foods are rich in Senkinnaitakusan?

1. Licorice sweets and licorice tea: they add more glycyrrhizin, the part that drops potassium
2. Salty foods: extra salt makes swelling and high blood pressure worse
3. Cinnamon and cassia in food or drinks: more exposure if you react to cinnamon

What are the side effects of Senkinnaitakusan?

• Swelling in the face, hands or ankles from held fluid
• Fast weight gain over a few days from held fluid
• A rise in blood pressure
• Low potassium (a blood mineral), causing muscle weakness and cramps
• Heavy, weak legs or muscle pain
• Rash, itching or hives, more likely if you react to cinnamon
• Nausea, stomach upset or loose stools
• Rare liver problems, with yellow skin, dark urine or deep tiredness
• Rare lung inflammation, with dry cough, fever and breathlessness

Good to know:

Most people who take it for a short course have no trouble. The main worry is the licorice in it.

Licorice can cause pseudoaldosteronism. That is a false hormone effect: the body holds salt and water, blood pressure climbs and potassium falls. It is more likely with higher doses, long use, in older people, and in women.

Very low potassium can weaken muscles and upset heart rhythm. This is uncommon, but it is the reason for the checks above.

How much Senkinnaitakusan should you take?

• Recommended daily: In Japan a common adult amount is 7.5 g of extract granules a day. That is split into two or three doses. Always follow the label and your doctor, because makers differ. No safe dose is set for use outside medical care. Because of the licorice, use the lowest dose that helps.
• Best time of day: Two or three doses spread through the day. Kampo granules are usually taken before meals or between meals.
• With or without food: On an empty stomach, about 30 minutes before food, is the usual Kampo way. If it upsets your stomach, take it with a little food.
• Time to effect: Not established by trials. In traditional use a change is looked for within one to two weeks. If nothing has changed in two weeks, speak to your doctor.
• How long to take it: Short courses are the norm. Look at how you are doing after two to four weeks. Risk from licorice grows with a higher dose and longer use. If you stay on it, ask for blood pressure checks and a blood test for potassium. Stop and get advice if the sore is no better after a month.