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Limited evidenceGeneral health

Yellow Dock

A bitter root traditionally used as a gentle laxative and a tonic for iron. It contains anthraquinones that plausibly explain the laxative effect, but no human trial has been published, and it will not supply iron.

Evidence last reviewed: August 2026

What the science says

  • Laxative action Limited evidence

    A comprehensive review of Rumex crispus documents anthraquinone constituents of the same class that make senna and rhubarb work, which supports a plausible stimulant laxative effect. No clinical trial of yellow dock as a laxative exists.

  • It does not treat iron deficiency Limited evidence

    The root contains very little iron and is high in oxalate, which binds iron rather than delivering it. The traditional association is with bitter digestive stimulation, not with correcting anaemia, which requires diagnosed treatment with iron salts.

  • Other activity is preclinical Limited evidence

    Laboratory studies report α-glucosidase inhibition and antihyperglycaemic activity of Rumex crispus extracts in animal models. This is early-stage work with no human follow-up.

Dosage & safety

Studied doseNo studied dose. Traditional use is 1–2 g of dried root as a decoction, or 1–2 mL of tincture, up to three times daily, and stimulant laxative herbs should not be used continuously for more than about a week.
SafetyHigh in oxalate: cases of severe and fatal oxalate poisoning have been reported after eating large quantities of Rumex leaves, and it is a poor choice for anyone with a history of calcium oxalate kidney stones or kidney disease. As an anthraquinone laxative it can cause cramping and, with chronic use, electrolyte loss. Avoid in pregnancy, breastfeeding and bowel obstruction.

Scientific references

Where to buy

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