Supplement analysis backed by scientific evidence · PT

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Limited evidenceGeneral health

Kidney Support Formulas

Herbal blends — typically uva ursi, nettle, dandelion, parsley and cranberry — marketed for kidney and urinary health. There is no evidence that they support kidney function, and herbal products are a documented cause of kidney injury.

Evidence last reviewed: August 2026

What the science says

  • Uva ursi for urinary symptoms Moderate evidence

    Two randomised trials tested uva ursi extract in women with uncomplicated urinary tract infection. In the ATAFUTI factorial trial it did not significantly reduce symptoms, and in a trial against fosfomycin the uva ursi group had a greater symptom burden and more cases progressing to pyelonephritis. The best-studied ingredient in these blends performed worse than the comparator.

  • Supporting kidney function Limited evidence

    No randomised trial has shown that any consumer herbal blend improves glomerular filtration rate, slows chronic kidney disease or protects the kidneys. "Kidney support" is a marketing category, not a demonstrated pharmacological effect.

  • Herbs can damage kidneys Moderate evidence

    Reviews of herbal nephropathy document acute and chronic kidney injury from herbal products, most notoriously aristolochic acid nephropathy, along with contamination and adulteration cases. The risk runs in the opposite direction to the claim on the label.

Dosage & safety

Studied doseNo validated dose. Blends usually supply several herbal extracts at 200–500 mg each. Uva ursi in particular should never be taken long term.
SafetyUva ursi contains hydroquinone precursors and should not be used for more than about a week or repeatedly. Anyone with reduced kidney function should not take herbal blends without nephrology advice — impaired clearance raises exposure, and potassium- or oxalate-rich botanicals can be dangerous. Diuretic herbs interact with lithium, diuretics and antihypertensives. Aristolochia contamination is a real risk with unregulated products, and it causes irreversible kidney failure and urothelial cancer.

Scientific references

Where to buy

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