What is Goreisan (Kampo)?

Goreisan is a classical herbal formula with over 1,800 years of history, originally recorded in the Chinese medical text Shang Han Lun (c. 200 CE) and later adopted into Japanese Kampo medicine. It combines five ingredients — Poria, Alisma, Polyporus, Atractylodes, and Cinnamon bark — each contributing to the body's ability to move and balance fluid. In Japan today, it is one of the most widely prescribed Kampo formulas and is officially approved as a prescription medicine under the Japanese healthcare system.

How does Goreisan (Kampo) work?

Goreisan is thought to support the kidneys' ability to regulate water channels in the body, helping shift excess fluid out through urine while relieving related symptoms like bloating, thirst, headache, and dizziness. Modern research suggests it may work in part by influencing aquaporins — the tiny proteins that control how water moves in and out of cells — as well as by supporting kidney filtration and reducing fluid buildup in tissues. The cinnamon component is believed to help circulate warmth and improve blood and fluid movement throughout the body.

What forms does Goreisan (Kampo) come in?

In Japan, Goreisan is almost universally available as standardized granule extracts (e.g., Tsumura TJ-17), which dissolve in warm water or can be swallowed directly. These are the same preparations used in clinical trials and hospital settings. Traditional decoction (boiling the raw herbs) is also used by practitioners but is less convenient. Tablets and capsules exist in international markets. For clinical results, standardized granule extracts from established Kampo manufacturers are preferred.

Where it comes from:

Goreisan (called Wu Ling San in Chinese medicine) originates from the Shang Han Lun, one of the oldest clinical medicine texts in East Asian history, written by Zhang Zhongjing around 200 CE. It has been used continuously for nearly two millennia across China, Japan, and Korea. In Japan, it was incorporated into the formal Kampo system during the Edo period and today holds official prescription drug status. It remains among the top 20 most-prescribed Kampo formulas in Japanese hospitals and clinics.

What does Goreisan (Kampo) help with?

• Fluid retention and edema: Goreisan helps the body move excess fluid through the kidneys rather than letting it pool in tissues. It is particularly suited for people who feel puffy or swollen but also feel thirsty — a pattern traditional medicine calls 'water stagnation.'
• Dizziness and vertigo: Many cases of dizziness in traditional medicine are linked to fluid imbalance in the inner ear or head. Goreisan is commonly used in Japanese neurology and ENT clinics for vertigo, including Meniere's-type symptoms, by helping normalize fluid pressure in these areas.
• Headache with nausea or thirst: The type of headache Goreisan targets is often described as a heavy, pressured feeling — sometimes with nausea or strong thirst but little urination. These headaches may relate to fluid retention or hangover, and Goreisan helps resolve them by restoring normal fluid movement.
• Hangover symptoms: Goreisan is one of the most popular hangover remedies in Japan. Alcohol disrupts the body's water-handling systems, and Goreisan helps restore normal fluid balance, easing the headache, nausea, and fatigue that come with it.
• Chronic subdural hematoma (fluid reabsorption support): Several Japanese neurosurgical studies have used Goreisan as an adjunct treatment after draining chronic subdural hematomas — pockets of old blood and fluid on the brain surface — finding it may help reduce recurrence by supporting fluid reabsorption. This is an evidence-supported use specific to Kampo neurology practice.
• Post-surgery or post-procedure fluid buildup: Goreisan has been studied for managing fluid collections that sometimes form after surgery or drainage procedures, including after neurosurgery. It is used to help the body reabsorb residual fluid naturally.
• Meniere's disease symptoms: Meniere's disease involves fluid pressure buildup in the inner ear causing episodes of vertigo, tinnitus, and hearing changes. Goreisan is used in Japanese ENT practice to help regulate this fluid pressure and reduce the frequency of episodes.
• Low urine output: When the body retains too much fluid and urination is reduced — especially alongside thirst — Goreisan gently promotes kidney filtration to restore normal urine flow without the harsh effect of pharmaceutical diuretics.
• Motion sickness and fluid-related nausea: The formula has a settling effect on fluid-related nausea and dizziness, making it useful for motion sickness or any nausea tied to fluid imbalance rather than infection.
• Kidney stone prevention (recurrence): Some Japanese urological research has explored Goreisan for reducing the recurrence of calcium oxalate kidney stones, likely through its mild diuretic effect and ability to improve urinary flow and composition.

What can Goreisan (Kampo) help prevent?

• Recurrence of chronic subdural hematoma after surgical drainage
• Recurrence of ureteral/kidney stones (calcium oxalate type)

Which foods are rich in Goreisan (Kampo)?

1. Coix (Job's Tears / Hato Mugi): A grain widely used in East Asian food and medicine with mild diuretic and anti-inflammatory properties that support the same fluid-clearing effect as Goreisan.
2. Barley water: Traditional diuretic food across many cultures; supports kidney filtration and fluid movement in a similar direction to Goreisan's core action.
3. Watermelon (including rind): High water content with natural citrulline and mild diuretic compounds; supports urinary output and fluid balance.
4. Cucumber: Hydrating and mildly diuretic; supports the kidney-draining, fluid-regulating direction of Goreisan's action.
5. Green tea: Contains mild diuretic compounds and is frequently consumed alongside Kampo formulas in Japanese practice to support hydration and kidney function.

Practical Tips:

Goreisan itself is not found in food — it is a concentrated herbal formula. The foods listed above share similar fluid-regulating and mildly diuretic properties and can complement Goreisan's effects as part of a supportive diet. Reducing sodium and processed foods is also important for managing the fluid retention conditions Goreisan addresses.

What are the side effects of Goreisan (Kampo)?

• Mild digestive discomfort or loose stools (uncommon)
• Skin rash or itching (rare allergic reaction)
• Excessive urination if combined with other diuretics
• Electrolyte imbalance with prolonged high-dose use (rare)
• Elevated aldosterone-related effects from licorice are NOT a concern here — Goreisan does not contain licorice (unlike many other Kampo formulas)

Good to know:

Goreisan has a long safety record and is generally considered very well tolerated when used as directed. As a prescription Kampo medicine in Japan, it has been used in large patient populations with close monitoring.

How much Goreisan (Kampo) should you take?

• Recommended daily: 7.5 g/day of standardized Kampo granule extract (e.g., Tsumura TJ-17), typically divided into 2–3 doses — this is the Japanese prescription standard dose
• Best time of day: Traditionally taken before meals — approximately 30 minutes before eating — to optimize absorption; in practice, 2–3 times daily before meals
• With or without food: Traditionally taken before meals (fasting state), dissolved in warm water or swallowed with warm water; avoid cold water which may reduce effectiveness in traditional practice
• Time to effect: Acute symptoms (headache, hangover, dizziness) may improve within 1–3 days; chronic fluid conditions typically respond within 2–4 weeks of consistent use
• How long to take it: For acute use (hangover, headache): as needed, short term. For chronic conditions (edema, Meniere's, post-surgical fluid management): typically 4–12 weeks under practitioner guidance, with reassessment. Long-term use is common in Japanese clinical practice under monitoring.