Supplement analysis backed by scientific evidence · PT

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Limited evidenceGeneral health

Punarnava

An Ayurvedic herb (Boerhavia diffusa) used traditionally as a diuretic and kidney tonic. Essentially all of the published pharmacology is in cells and rodents; there are no controlled human trials of the single herb.

Evidence last reviewed: August 2026

What the science says

  • Diuretic and kidney-protective effects Limited evidence

    A comprehensive pharmacology review catalogues diuretic, nephroprotective and anti-inflammatory effects, but the underlying studies are cell-culture and rodent experiments. No randomised human trial has tested punarnava for kidney function or fluid retention.

  • Product identity is unreliable Limited evidence

    An HPLC fingerprinting survey of Boerhavia diffusa sold in Indian markets found substantial variation between samples, and the species is known to be substituted with look-alike plants. What is in the capsule may not be what is on the label.

Dosage & safety

Studied doseTraditional use is roughly 1–3 g/day of root powder, or 250–500 mg of extract on typical labels. No dose has been validated in humans.
SafetyHuman safety data are essentially absent. Because it is promoted as a diuretic, it should not be self-prescribed by anyone with kidney disease, heart failure or on diuretics, lithium or other drugs sensitive to fluid and electrolyte shifts. Avoid in pregnancy — traditional texts describe abortifacient use. Adulteration is a documented problem.

Scientific references

Where to buy

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