What is Jizusoippo?

Jizusoippo is a Kampo herbal formula from Japan. It is a set blend of nine dried herbs. It is used for itchy, crusty or weeping rashes on the head and face.

Japan's health ministry (MHLW) lists it among the 148 Kampo formulas approved for national health insurance (the NHI-approved list of 148). Doctors there may prescribe it for eczema (an itchy, inflamed skin rash) on the scalp, for cradle cap in babies, or for sore patches in the hair.

Here is the honest verdict. The formula has a long record of use in Kampo, but that record is not proof that it works. We could not find published human trials of Jizusoippo itself.

How does Jizusoippo work?

No one has shown how Jizusoippo works in the body. Kampo theory says it clears "heat" and "damp" from the upper body and gets stuck blood moving again. Those are traditional ideas, not tested biology.

In modern terms, several of the herbs calm swelling in lab dishes and in animals. Rhubarb root also works as a mild laxative (a bowel-loosening agent). Lab results like these do not tell you what will happen on a child's skin.

So treat any explanation you read as a story, not a proven path. The safety effects of the formula are much better mapped than the benefits.

What forms does Jizusoippo come in?

In Japan it is sold mostly as a dried extract granule or fine powder, in single-dose sachets. Tablets and capsules of the same extract are also made.

Traditional practice uses a decoction: the raw herbs are simmered in water and the liquid is drunk. This is less common now.

It is a swallowed medicine. It is not a cream, and the granules are not meant to be rubbed on the skin.

Where it comes from:

The name means roughly "the one formula for head sores". It grew out of Japanese practice in the Edo period (1603-1868), built from bedside experience rather than copied from a Chinese classic.

It has stayed in use in Kampo ever since, mainly for children with scalp and face rashes. Japanese makers still produce it today, and it sits on the country's insurance-approved formula list.

What does Jizusoippo help with?

• Eczema and dermatitis on the scalp and face: This is the main traditional use, and the reason Japanese doctors reach for it. Kampo texts point to rashes that are red, hot and weeping rather than dry and pale. We could not find any published human trial testing Jizusoippo for this. So the use rests on practice and case reports only.
• Cradle cap in babies: Kampo practice has long used this formula for greasy, crusted patches on an infant's scalp. Doses are cut right down for babies. There is no trial evidence here at all. Cradle cap also clears on its own in most babies, which makes any uncontrolled report hard to read. Never give it to a baby without a doctor's guidance.
• Weeping or scabby sores in the hair: Traditional use covers sores that ooze and crust over. Modern medicine would first want to rule out a bacterial or fungal infection, which needs its own treatment. No human trials support the formula for this. If a sore is spreading, hot or painful, see a doctor rather than self-treating.
• Childhood atopic dermatitis affecting the head: Some Japanese practitioners add it alongside standard care for children whose atopic rash sits mainly on the scalp and face. It is used as an add-on, not a swap for prescribed creams. The evidence is practice-based. No controlled human study of this formula has been published that we could identify.
• Itchy scalp with redness and flaking: Tradition frames this as "heat" in the upper body, which the formula is said to cool. Reported use is mostly in the short term, over a few weeks. Again, no trial has tested this. Long-term use raises the licorice risks listed under safety, so it is not a formula to take month after month without checks.

Which foods are rich in Jizusoippo?

1. Licorice sweets and licorice root tea: they add to the glycyrrhizin already in the formula
2. Salty miso, soy sauce and pickles: extra salt worsens the swelling and blood pressure rise licorice can cause
3. Rhubarb-based herbal laxative teas: they add to the bowel-loosening effect

What are the side effects of Jizusoippo?

• Loose stools or diarrhoea, from the rhubarb root
• Stomach ache or cramping
• Nausea or loss of appetite
• Skin rash, itching or hives as an allergic reaction
• Swelling of the face, hands or ankles
• A rise in blood pressure
• Muscle weakness, cramps or an odd heartbeat, which can point to low potassium
• Rarely, signs of liver irritation such as yellow skin or eyes, dark urine or deep tiredness

Good to know:

Mild bowel upset is the most likely problem, because the formula contains rhubarb root. It usually settles when the dose is lowered.

The serious concern is the licorice root. Over weeks it can cause pseudoaldosteronism (a licorice reaction that drops your potassium, raises your blood pressure and puffs up your face and legs). Low potassium can weaken muscles and upset the heart's rhythm.

Liver injury has been reported with Kampo formulas in general. It is rare, but it is the reason the warning signs are listed above.

How much Jizusoippo should you take?

• Recommended daily: In Japan the usual adult dose of the dried extract granule is about 7.5 g a day, split into two or three doses. Makers vary, so follow the label on the pack you hold. Children get far less, scaled to age or weight. A doctor or Kampo pharmacist should set a child's dose. Outside Japan no standard dose is established. Because the blend contains licorice and rhubarb, do not guess at your own amount.
• Best time of day: Japanese practice gives it two or three times a day, spread across the day. Take it at the same times each day. If the rhubarb in it loosens your bowels too much, tell your prescriber rather than shifting the timing yourself.
• With or without food: Kampo granules are usually taken before meals or between meals, on a fairly empty stomach. Warm water helps the granules dissolve. If it upsets your stomach, taking it with a little food is reasonable. Ask your prescriber first.
• Time to effect: Kampo practice expects some change in one to two weeks, though skin often moves more slowly. No trial evidence supports any timeline, so treat this as custom rather than fact.
• How long to take it: Short courses are the norm. Kampo practice reviews progress after about two to four weeks and stops if nothing has changed. If you take it for more than a few weeks, ask your doctor to check your blood pressure and your blood potassium (a mineral your heart needs). Licorice problems build up quietly over weeks to months.