What is Goreisan?

Goreisan is a traditional five-herb Kampo formula that has been used in Japan and China for over a thousand years to correct what classical medicine calls 'water metabolism disorder' — basically, the body's inability to move and distribute fluids properly. It combines diuretic, circulatory, and digestive herbs that work together to reduce abnormal fluid accumulation while supporting healthy water transport. In modern Japan, it is an officially approved prescription Kampo medicine covered by national health insurance.

How does Goreisan work?

The formula works through several complementary mechanisms: its key herb Alisma rhizome acts as a gentle diuretic by influencing how the kidneys handle water and electrolytes, while Poria and Polyporus support lymphatic and cellular fluid movement. Cinnamon bark warms and activates circulation, helping the body redirect stagnant fluids. Together, the herbs appear to modulate aquaporin water channel proteins — the molecular 'gates' that control how water moves in and out of cells — which may explain the formula's effects on conditions like brain fluid imbalance and inner ear fluid excess.

What forms does Goreisan come in?

In Japan, Goreisan is most commonly dispensed as standardized granules (TJ-17 by Tsumura is the benchmark commercial product) that dissolve in warm water or are taken directly. These granules are used in virtually all modern clinical trials. Traditional decoction requires boiling the five raw herbs together. Tablets and powders are also available through Kampo pharmacies and specialty supplement retailers outside Japan.

Where it comes from:

Goreisan originates from the 'Shang Han Lun' (Treatise on Cold Damage Diseases), a foundational Chinese medical text compiled around 200 CE by Zhang Zhongjing. It was adopted into Japanese Kampo practice and has remained continuously in use for over 800 years in Japan. Today it is one of the most prescribed Kampo formulas in Japanese hospitals, particularly in neurology and geriatrics, and has attracted modern clinical interest for conditions ranging from chronic subdural hematoma to Meniere's disease.

What does Goreisan help with?

• Fluid retention and edema: Goreisan helps the body move and eliminate excess fluid that has pooled in tissues, particularly in the legs, face, and abdomen. It does this gently — more like a regulator than a harsh diuretic — so fluid levels normalize without the crash that can come with strong pharmaceutical diuretics.
• Normal pressure hydrocephalus: This is one of Goreisan's most studied modern applications. It appears to help regulate cerebrospinal fluid (CSF) production and absorption, easing the pressure buildup that causes the classic triad of gait problems, memory issues, and urinary symptoms. Japanese neurology clinics now routinely use it alongside or instead of surgery in appropriate patients.
• Chronic subdural hematoma: Blood pooling between the brain and skull (chronic subdural hematoma) involves abnormal fluid accumulation that can be hard to resolve. Goreisan has been shown in Japanese clinical studies to reduce recurrence rates after surgical drainage and may help reabsorb small collections that don't require surgery.
• Dizziness and vertigo (fluid-related): When dizziness stems from fluid imbalance — whether in the inner ear or in the brain's pressure regulation — Goreisan can help stabilize the underlying fluid dynamics rather than just masking the spinning sensation.
• Meniere's disease and inner ear fluid imbalance: Meniere's disease involves excess fluid (endolymph) in the inner ear. Goreisan's ability to regulate fluid transport may help reduce the frequency and severity of episodes, including vertigo attacks and hearing fluctuation, without the side effects of diuretic drugs.
• Post-concussion headache and symptoms: After a head injury, disrupted CSF flow and pressure changes can cause lingering headache, brain fog, and dizziness. Goreisan is used in Japanese sports and neurology medicine to support recovery by normalizing intracranial fluid dynamics.
• Nausea and vomiting from fluid imbalance: Traditional Kampo use for nausea caused by fluid stagnation — such as motion sickness, morning sickness, or nausea paired with thirst and poor urination — is well established. The formula helps restore proper digestive fluid movement.
• Hangover symptoms: Goreisan is widely used in Japan for hangover relief, targeting the dehydration and fluid redistribution disruption that alcohol causes. Users often report faster resolution of headache, nausea, and fatigue compared to rest alone.

What can Goreisan help prevent?

• Recurrence of chronic subdural hematoma after surgical drainage
• Progression of normal pressure hydrocephalus symptoms when started early

Which foods are rich in Goreisan?

Goreisan is a multi-herb formula with no direct food equivalent — you cannot replicate it through diet. However, foods that support fluid balance and healthy kidney function work along the same pathway. Prioritize: (1) Coix seed (Job's tears) — a traditional East Asian grain with clinically studied mild diuretic and anti-inflammatory effects; (2) Adzuki beans — used in both Chinese and Japanese medicine to gently support fluid drainage and reduce edema; (3) Watermelon and cucumber — high water content with natural diuretic compounds that support kidney filtration; (4) Celery — contains phthalides that support healthy blood pressure and fluid balance; (5) Green tea — contains compounds that mildly support fluid metabolism and aquaporin activity. Reducing sodium, alcohol, and ultra-processed foods directly counters the fluid retention patterns Goreisan addresses. Staying consistently well-hydrated (paradoxically) helps the kidneys regulate fluid more efficiently.

What are the side effects of Goreisan?

• Mild stomach upset or loose stools (uncommon, usually resolves with food)
• Skin rash or itching (rare allergic reaction, discontinue if it occurs)
• Electrolyte changes with very long-term high-dose use (monitor potassium in at-risk patients)
• Elevated liver enzymes in rare cases (seen across many Kampo formulas; monitor with prolonged use)
• Excessive urination if combined with other diuretics

Good to know:

Goreisan has an excellent safety profile established over centuries of use and confirmed in modern Japanese post-marketing surveillance involving tens of thousands of patients. Serious adverse effects are rare. It is considered safe for most adults, including the elderly, when taken at standard doses.

How much Goreisan should you take?

• Recommended daily: Standard Japanese Kampo prescription: 7.5 g of standardized granules per day (e.g., Tsumura TJ-17), divided into 2–3 doses. This corresponds to approximately 5 g of crude herb per component herb in the traditional ratio. Western supplement products vary — follow manufacturer guidance and confirm standardization to traditional ratios.
• Best time of day: Traditionally taken before meals — 30 minutes before eating, three times daily. This is the standard approach in Japanese Kampo prescribing.
• With or without food: Best taken before meals or on a relatively empty stomach for absorption; if stomach sensitivity occurs, taking with a small amount of warm water or light food is acceptable.
• Time to effect: Acute fluid symptoms (nausea, dizziness, hangover) may respond within 1–3 days. Chronic conditions like edema, hydrocephalus, or subdural hematoma management typically require 4–12 weeks of consistent use before meaningful improvement is seen.
• How long to take it: For acute conditions (hangover, mild edema): use as needed, short-term. For chronic conditions (NPH, chronic subdural hematoma, Meniere's): minimum 3-month trial is standard in Japanese clinical practice, with reassessment at that point. Long-term use beyond 6 months should be supervised by a knowledgeable practitioner with periodic liver enzyme and electrolyte monitoring.