Natural Herb Library

Root of Thinleaf Milkwort

Chinese
远志
Pinyin
Yuan Zhi
Latin
Radix Polygalae
Botanical illustration of Root of Thinleaf Milkwort, Polygala tenuifolia, showing Yuan Zhi root material and diagnostic source details.
Botanical plate by Kodi .

Known in TCM as Yuan Zhi (远志), this bitter and acrid, slightly warm herb enters the Heart, Kidney, and Lung. Traditionally, it calms the spirit and quiets the Heart ... Yuan Zhi is a classic root for insomnia, palpitations, anxiety, and agitation when Heart and Kidney communication is disturbed, most often applied for insomnia, forgetfulness, and palpitations. Modern research has identified Tenuifolin among its active constituents.

Part used: Root

Also Known As

Polygalae Radix Yuan Zhi Root

Latin: Radix Polygalae | Pinyin: Yuan Zhi | Chinese: 远志

TCM Properties

Taste
bitter, acrid
Temperature
slightly warm
Channels
Heart, Kidney, Lung

Traditional Use

Primary Actions

  • Calms the spirit and quiets the Heart ... Yuan Zhi is a classic root for insomnia, palpitations, anxiety, and agitation when Heart and Kidney communication is disturbed.
  • Expels phlegm and opens the orifices ... it is used when turbid phlegm clouds the mind, leading to poor focus, forgetfulness, or dull emotional heaviness.
  • Redirects Lung Qi and helps resolve cough with phlegm ... a secondary but important lane when mental and respiratory phlegm patterns overlap.

Secondary Actions

  • Yuan Zhi sits at the intersection of spirit-calming and phlegm-transforming herbology, which is why it appears in both mind and cough formulas.
  • The root is better known for attention, memory, and sleep support than for raw ornamental milkwort identity.

Classic Formulas

  • Ding Zhi Wan ... classic formula pairing Yuan Zhi with Shi Chang Pu, Ren Shen, and Fu Ling for fright, poor focus, and disturbed Shen.
  • An Shen Ding Zhi Wan and related spirit-calming formulas ... Yuan Zhi helps reconnect Heart and Kidney while transforming obstructing phlegm.
  • Cough and phlegm pairings with Jie Geng, Zi Wan, or Bai Bu ... used when Lung phlegm and mental dullness coexist.

Classical References

  • Traditional materia medica treats Yuan Zhi as a key herb for communication between the Heart and Kidney and for opening the orifices through phlegm transformation.
  • Its dual mental and respiratory use explains why it appears in both insomnia and cough lineages.

Modern Research

Active Compounds

  • Tenuifolin and related triterpenoid saponins ... major Yuan Zhi marker compounds
  • Xanthones and oligosaccharide esters ... recurrent constituent classes in cognition-oriented research
  • Polygalic-acid-related fractions ... additional compounds relevant to neuroprotective and anti-inflammatory study

Studied Effects

  • A 2020 review on Polygalae Radix covered traditional uses, phytochemistry, pharmacology, toxicology, and pharmacokinetics and remains one of the strongest single-source overviews for Yuan Zhi (PMID 33069838).
  • A 2024 review of Polygalae Radix metabolites, pharmacological activities, and toxicology showed how wide the modern evidence lane has become, especially for neuroprotection and psychopharmacology (PMID 38873413).
  • A 2020 review positioned Polygala tenuifolia as a source for anti-Alzheimer's disease drug discovery, reinforcing why Yuan Zhi attracts so much modern cognition-focused research (PMID 32429787).

PubMed References

Safety & Interactions

Contraindications

  • Gastric or esophageal irritation worsened by acrid dispersing roots
  • Yin deficiency with significant heat if the formula already runs too warm and drying

Cautions

  • Yuan Zhi can irritate the stomach in some people, especially at larger doses or in concentrated preparations.
  • Modern cognition-focused extracts are not interchangeable with traditional decoction dosing.

Conditions

Frequently Asked Questions

What is Root of Thinleaf Milkwort used for?

Root of Thinleaf Milkwort is traditionally used to Calms the spirit and quiets the Heart ... Yuan Zhi is a classic root for insomnia, palpitations, anxiety, and agitation when Heart and Kidney communication is disturbed., Expels phlegm and opens the orifices ... it is used when turbid phlegm clouds the mind, leading to poor focus, forgetfulness, or dull emotional heaviness., Redirects Lung Qi and helps resolve cough with phlegm ... a secondary but important lane when mental and respiratory phlegm patterns overlap.. Research has investigated its effects on: A 2020 review on Polygalae Radix covered traditional uses, phytochemistry, pharmacology, toxicology, and pharmacokinetics and remains one of the strongest single-source overviews for Yuan Zhi (PMID 33069838).; A 2024 review of Polygalae Radix metabolites, pharmacological activities, and toxicology showed how wide the modern evidence lane has become, especially for neuroprotection and psychopharmacology (PMID 38873413)..

What are other names for Root of Thinleaf Milkwort?

Root of Thinleaf Milkwort is also known as Polygalae Radix, Yuan Zhi Root. In TCM: 远志 (Yuan Zhi); Radix Polygalae.

Is Root of Thinleaf Milkwort safe during pregnancy?

The safety of Root of Thinleaf Milkwort during pregnancy has not been established. Consult a qualified healthcare provider before use.

What are the contraindications for Root of Thinleaf Milkwort?

Root of Thinleaf Milkwort should not be used in: Gastric or esophageal irritation worsened by acrid dispersing roots; Yin deficiency with significant heat if the formula already runs too warm and drying. Consult a qualified practitioner before use.