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Bian Xu萹蓄

Polygoni Avicularis Herba · Knotgrass · Common Knotgrass Herb

Herbs that Drain Dampness 利水渗湿药《神农本草经》

Overview

A common roadside knotgrass with one clear job: it opens the Bladder and drains damp-heat downward, easing burning, urgent, dripping urination — which is why it sits in Ba Zheng San. Decocted as a wash, its damp-drying, itch-settling side is turned on weeping skin and vaginal itching.

Nature & Flavor

Bitter · Slightly cold

Channels

Bladder

Typical Dosage

9–15 g in decoction
萹蓄Photography for this entry is on its way.

Actions

3 core actions

  • Promotes urination, eases painful urinationDamp-heat in the Bladder: burning, urgent, frequent or dripping urination, sometimes with gravel or blood.
  • Kills parasites, stops itchingDamp itching, weeping eczema and vaginal itching — mostly as an external wash.
  • Drains damp, relieves jaundiceDamp-heat jaundice, as a supporting herb within a larger formula.

In Formulas

Formulas containing Bian Xu

Indications & Clinical Uses

  • Damp-heat painful urination: burning, urgency, frequency
    - Urinary gravel or blood-streaked urine of damp-heat type
    - Damp itching, weeping eczema, vaginal itch (external wash)
    - Damp-heat jaundice

Western Medical Keywords

Searchable condition terms

Urinary tract infectionCystitisUrinary stonesEczema

Contraindications

Cautions

Draining and cooling: not for urinary frequency of deficiency, and prolonged use depletes both fluids and qi. Burning urination accompanied by fever, flank pain or vomiting points to an upper urinary tract infection and needs prompt medical assessment rather than herbs alone.

Contraindicated in pregnancy: Use with caution in pregnancy — practitioner supervision required

For licensed practitioners’ reference only

References

  1. Shen Nong Ben Cao Jing《神农本草经》(classical source, public domain).
    2. Bensky, Clavey & Stöger. Chinese Herbal Medicine: Materia Medica, 3rd ed.
    3. 《中华人民共和国药典》.

Professional reference notice. Entries are scholarly references for licensed TCM practitioners and students — not medical advice, and not a recommendation to self-prescribe. Chinese herbal formulas should be used under the guidance of a qualified practitioner. Content is an original editorial compilation by Cura x Cura, cross-checked against the cited references.