Educational information, not medical advice — ask your doctor or midwife.
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.
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.
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.
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.
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What it is typically used for, usual dose, cautions, and the study behind it where real trial data exists.
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