What is Goshuyu?

Goshuyu is the dried, unripe fruit of a small tree, Tetradium ruticarpum. In the West it is often sold as Evodia fruit. It is one of the single herbs used in Kampo, the Japanese school of herbal medicine.

Kampo uses it to warm a cold stomach. It is given for vomiting, watery spit-up and belly pain that feel worse in the cold. It is also used for a dull headache that comes with nausea and cold hands and feet.

The honest verdict: the traditional record is long and strong, but good human trials of Goshuyu on its own have not been published. A long history of use is not proof that a herb works, and that holds for everything in this library.

Read the safety part below before you try it. Goshuyu changes the way your body breaks down some common drugs, so it is not a herb to add on a whim.

How does Goshuyu work?

No one has shown how Goshuyu works in people. What follows is the best current thinking, not proven fact.

The fruit is sharp and hot on the tongue. Lab work suggests its main compounds act on nerve endings that sense heat and pain in the gut. That may be why Kampo describes the herb as warming the middle of the body and settling nausea.

One effect is well shown in lab and animal work. A compound called rutaecarpine speeds up CYP1A2, a liver enzyme (a body protein) that breaks down many medicines. When that enzyme works faster, some drugs are cleared too quickly and stop working as well.

That same finding is the reason this page carries a long interactions list. It is a safety fact, not a health benefit.

What forms does Goshuyu come in?

You will see Goshuyu in these forms:

Dried whole fruit, simmered in water to make a decoction (a strong tea).

Extract granules or powder, the usual form in Japanese pharmacies.

Capsules and tablets, often labelled Evodia, sold as a supplement in the West.

As one part of a Kampo formula. The best known is Goshuyuto, which pairs it with ginger, ginseng and jujube. Most traditional use is in a formula, not as a single herb.

Where it comes from:

Goshuyu is an old herb, not a new one. It appears in the Chinese classic Shang Han Lun, written around 200 CE, in the formula known there as Wu Zhu Yu Tang.

Chinese medicine, Korean medicine and Japanese Kampo all kept it. Kampo doctors of the Edo period (1603-1868) wrote it up in detail for cold-type vomiting and headache.

It is still made and prescribed in Japan today as a licensed Kampo ingredient.

What does Goshuyu help with?

• Vomiting and nausea of the cold type: This is the main traditional use, and it is well documented in Kampo texts. The picture is watery vomit, no thirst, a pale tongue and relief from warm drinks. There are no good human trials of Goshuyu alone for this, so treat it as tradition rather than proof.
• Dull headache with nausea: Kampo prescribes the formula Goshuyuto for a heavy, dull headache with nausea and cold limbs. Small Japanese reports and long practice support this use. We could not identify a well-run trial of the single herb, so the strength of the effect is unknown.
• Upper belly pain and bloating that eases with warmth: Traditional use only. The herb is described as warming a cold, weak stomach. Human evidence is absent, and belly pain has many causes, some serious. Get pain checked before treating it yourself.
• Sour belching and watery spit-up: Classical texts list this. Note the flip side: in some people the fruit burns and makes heartburn worse. If it worsens your symptoms, stop.
• Cold hands and feet with a weak stomach: A traditional pattern-based use rather than a proven one. Lab work shows the compounds can relax blood vessels in animals, but that has not been tested as a treatment in people.

Which foods are rich in Goshuyu?

1. No everyday food contains Goshuyu - the dried fruit is used as a medicine, not a kitchen spice
2. Sichuan pepper and citrus peel are sometimes confused with it, but they are different plants with different effects

Practical Tips:

You cannot get Goshuyu from your diet, and you do not need to.

What are the side effects of Goshuyu?

• Hot or burning feeling in the mouth and throat
• Dry mouth
• Heartburn or stomach burning
• Nausea that gets worse rather than better
• Loose stools or belly cramps
• Flushing of the face
• Headache or dizziness
• Skin rash or itching
• Rarely, changes in liver blood tests

Good to know:

Most reported effects are mild and settle when you stop. The fruit is sharp, so mouth and stomach burning are the common complaints.

Two things keep this herb out of the routine group. Animal studies using high doses have shown liver damage, and the herb speeds up the breakdown of several important medicines. Neither is a reason to panic at a small short course, but both are reasons to be careful and to tell your doctor you are taking it.

How much Goshuyu should you take?

• Recommended daily: No dose has been set by human trials. What follows is normal traditional practice, not a proven amount. In Kampo, about 1 to 3 grams of dried fruit a day is usual, and almost always inside a formula rather than alone. For extract granules, follow the label or your practitioner. Do not stack a granule product and loose fruit at the same time. Goshuyu is treated as a strong, slightly harsh herb. More is not better, and higher amounts raise the chance of burning and of drug interactions.
• Best time of day: Split the daily amount into two or three doses. Take it warm, shortly before meals. Some people take a dose at the first sign of a headache instead.
• With or without food: Traditionally taken on an empty stomach with warm water. If it burns or stings, take it with a little food instead, or stop.
• Time to effect: If it helps nausea, people usually notice within an hour or two. For belly comfort, give it a few days. If two weeks bring no change, it is not working for you.
• How long to take it: Short courses only. Kampo practice uses it for days to about two weeks for an acute problem. Stop and reassess if nothing has changed in two weeks. Long, steady use is not supported and has not been tested for safety in people.