Tong Cao通草
Tetrapanacis Medulla · Rice Paper Plant Pith · Tetrapanax Pith
Overview
The white pith of the rice paper plant, cut into weightless cylinders — the same material once shaved into sheets for painting. Sweet, bland and slightly cold, it drains damp-heat gently downward through the urine and opens the collaterals to free the flow of milk, which are its two working uses. One point of nomenclature matters clinically: in the early materia medica the name Tong Cao referred to the plant now called Mu Tong 木通, and today's Tong Cao is, a different plant entirely — a distinction worth insisting on when sourcing, since one historical member of the Mu Tong group contained aristolochic acid.
Nature & Flavor
Sweet, bland · Slightly coldChannels
Lung · StomachTypical Dosage
6–12 g in decoctionActions
2 core actions
- Promotes urination, drains damp-heatScanty, dark, hot or difficult urination, damp-heat in the lower burner, and mild edema. It leaches rather than forces, so it is used with stronger herbs when the damp is heavy.
- Frees the collaterals, promotes lactationSparse or blocked milk after childbirth, classically simmered in a nourishing soup or given with Wang Bu Liu Xing.
In Formulas
Formulas containing Tong Cao
Indications & Clinical Uses
- Scanty, dark or painful urination from damp-heat
- Mild edema with reduced urine output
- Insufficient or blocked breast milk after childbirth
Western Medical Keywords
Searchable condition terms
Contraindications
Cautions
Bland and draining, so it is unsuitable where fluids are already depleted — copious clear urine, a dry mouth with a peeled tongue, or frank yin deficiency — and it is not taken continuously. It should never be substituted for or confused with Mu Tong 木通: the Manchurian species once sold under that name, Guan Mu Tong, contains aristolochic acid and caused irreversible kidney damage and urinary tract cancers, and it has been banned as a result. Buy Tong Cao that is identified as Tetrapanax pith. Painful urination with fever or back pain needs medical assessment.
Contraindicated in pregnancy: Use in pregnancy only under practitioner supervision — it drains downward and promotes urination, and traditional practice has always been cautious with it during pregnancy.
For licensed practitioners’ reference only
References
- Bensky, Clavey & Stöger. Chinese Herbal Medicine: Materia Medica, 3rd ed.
2. 《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.