Natural Herb Library

Vietnamese Sophora Root

Chinese
山豆根
Pinyin
Shan Dou Gen
Latin
Radix Sophorae Tonkinensis
Botanical illustration of Vietnamese Sophora Root, Sophora tonkinensis, showing medicinal roots, dried root pieces, and diagnostic plant details.
Botanical plate by Kodi .

Known in TCM as Shan Dou Gen (山豆根), this bitter, cold herb enters the Lung and Stomach. Traditionally, it clears heat and resolves toxin ... Shan Dou Gen is a classic herb for severe swollen sore throat, fire-toxin in the throat, and hot painful oral inflammation, most often applied for sore throat, pharyngitis, and tonsillitis. Modern research has identified Quinolizidine among its active constituents.

Part used: Root

Also Known As

Shan Dou Gen Guang Dou Gen Sophora tonkinensis root

Latin: Radix Sophorae Tonkinensis | Pinyin: Shan Dou Gen | Chinese: 山豆根

TCM Properties

Taste
bitter
Temperature
cold
Channels
Lung, Stomach

Traditional Use

Primary Actions

  • Clears heat and resolves toxin ... Shan Dou Gen is a classic herb for severe swollen sore throat, fire-toxin in the throat, and hot painful oral inflammation.
  • Benefits the throat and reduces swelling ... it is chosen when redness, pain, and difficult swallowing show a strong toxic-heat pattern.
  • Drains toxic fire from the Lung and Stomach territory ... traditional use extends to hot gum, mouth, and upper-respiratory inflammatory presentations.

Secondary Actions

  • This page must stay clearly separate from `root-of-lightyellow-sophora` ... Shan Dou Gen and Ku Shen share a genus but not the same source plant, clinical lane, or safety profile.
  • Its intensely bitter toxic-cold nature makes it a narrower and more forceful throat herb than gentler heat-clearing alternatives.

Classic Formulas

  • Shan Dou Gen Wan ... classic sore-throat and heat-toxin formula logic.
  • Qing Liang San style pairings with Lian Qiao, Jie Geng, or other throat-relieving herbs ... when wind-heat and toxin overlap.
  • Yin-deficiency throat-fire modifications with Xuan Shen and Mai Men Dong ... used when swelling and pain coexist with dryness.

Classical References

  • Traditional herbology describes Shan Dou Gen as bitter, cold, and toxic, entering the Lung and Stomach to clear heat, resolve toxin, benefit the throat, and reduce swelling.
  • Its bean-like odor and extremely bitter taste are repeatedly noted in materia medica discussions, underscoring both potency and narrowness of use.

Modern Research

Active Compounds

  • Quinolizidine alkaloids such as matrine-related constituents
  • Flavonoids and related anti-inflammatory secondary metabolites
  • Other root and rhizome fractions discussed in toxicology and detoxification reviews

Studied Effects

  • A 2025 comprehensive review covered ethnopharmacology, phytochemistry, pharmacology, pharmacokinetics, toxicology, and detoxification strategy of Sophorae tonkinensis radix et rhizoma, making it the best modern overview for Shan Dou Gen (PMID 39244176).
  • A 2019 study isolated quinolizidine alkaloids from Sophora tonkinensis and reported anti-inflammatory activities, supporting the root's traditional heat-toxin role (PMID 31682871).
  • A 2017 mouse study documented hepatotoxicity induced by Radix Sophorae tonkinensis and proposed serum cholinesterase as a supplemental biomarker, reinforcing why this herb needs a tighter safety frame than many throat remedies (PMID 28126209).

PubMed References

Safety & Interactions

Contraindications

  • Pregnancy
  • Weak digestion or deficiency-cold without toxic heat
  • Known liver vulnerability or unsupervised long-course use

Cautions

  • Shan Dou Gen is a toxic bitter-cold root and has a narrower safety margin than many common sore-throat herbs.
  • The distinction from Ku Shen matters clinically because source plant, toxicity emphasis, and indication set are different.

Conditions

Frequently Asked Questions

What is Vietnamese Sophora Root used for?

Vietnamese Sophora Root is traditionally used to Clears heat and resolves toxin ... Shan Dou Gen is a classic herb for severe swollen sore throat, fire-toxin in the throat, and hot painful oral inflammation., Benefits the throat and reduces swelling ... it is chosen when redness, pain, and difficult swallowing show a strong toxic-heat pattern., Drains toxic fire from the Lung and Stomach territory ... traditional use extends to hot gum, mouth, and upper-respiratory inflammatory presentations.. Research has investigated its effects on: A 2025 comprehensive review covered ethnopharmacology, phytochemistry, pharmacology, pharmacokinetics, toxicology, and detoxification strategy of Sophorae tonkinensis radix et rhizoma, making it the best modern overview for Shan Dou Gen (PMID 39244176).; A 2019 study isolated quinolizidine alkaloids from Sophora tonkinensis and reported anti-inflammatory activities, supporting the root's traditional heat-toxin role (PMID 31682871)..

What are other names for Vietnamese Sophora Root?

Vietnamese Sophora Root is also known as Shan Dou Gen, Guang Dou Gen, Sophora tonkinensis root. In TCM: 山豆根 (Shan Dou Gen); Radix Sophorae Tonkinensis.

Is Vietnamese Sophora Root safe during pregnancy?

Vietnamese Sophora Root is not recommended during pregnancy.

What are the contraindications for Vietnamese Sophora Root?

Vietnamese Sophora Root should not be used in: Pregnancy; Weak digestion or deficiency-cold without toxic heat; Known liver vulnerability or unsupervised long-course use. Consult a qualified practitioner before use.