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Limited evidenceSleep & relaxation

Poria Cocos (Fu Ling)

A fungus used for centuries in Chinese medicine to 'calm the spirit' and drain dampness, and a component of many classical sleep formulas. Evidence in humans is confined to multi-herb formulas, with no trial of Poria on its own.

Evidence last reviewed: August 2026

What the science says

  • Sedative activity in animals Limited evidence

    Pachymic acid, a triterpene from Poria cocos, prolonged pentobarbital-induced sleeping time in mice through GABA-A-ergic pathways. This supports a plausible mechanism but is a rodent hypnotic-potentiation model, not a clinical sleep outcome.

  • Use in traditional insomnia formulas Limited evidence

    A review of traditional Chinese herbal medicine for insomnia describes Poria cocos as a frequent constituent of classical multi-herb prescriptions used for sleep. Where trials of those formulas exist, they cannot attribute any effect to Poria specifically.

  • Diuretic and fluid-balance effects Limited evidence

    A multidimensional review of Poria cocos summarises diuretic, immunomodulatory and anti-inflammatory activity, largely from animal and in vitro work. Controlled human data on urine output or oedema are lacking.

Dosage & safety

Studied doseNo clinically studied isolated dose. Traditional decoction use is 9–15 g of the dried sclerotium per day within a formula; extract capsules typically list 500–1000 mg as a label dose.
SafetyLong culinary and medicinal use with few reported problems, but formal human safety studies are absent. Because of its traditional diuretic action, use caution with diuretic drugs and in people with electrolyte disturbances. Avoid in pregnancy and breastfeeding for lack of data, and be aware that wild-harvested fungal products vary widely in quality.

Scientific references

Where to buy

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