Zi Wan (紫菀) — Tatarian Aster Root: TCM Uses, Versatile Cough & Formulas

At a Glance

Herb: Zi Wan
Chinese name: 紫菀 (Zǐ Wǎn)
Latin name: Aster tataricus root and rhizome
Nature: Slightly Warm
Taste: Bitter / Sweet
Meridian: Lung
Category: Herbs that Resolve Phlegm and Stop Coughing
Introduction: Zi Wan (紫菀), the dried root and rhizome of Aster tataricus L. f. (Tatarian aster), is one of TCM’s most versatile cough-stopping herbs, suitable for virtually any type of cough regardless of whether it arises from cold or heat, deficiency or excess, exterior or interior. Recorded in the Shen Nong Ben Cao Jing, its bitter-sweet, warm-but-moist nature allows it to simultaneously resolve phlegm, descend lung qi, and moisten the lung — a combination that avoids the drying tendency of purely warm herbs. Modern pharmacology has confirmed astersaponin, shionone, quercetin, and epifriedelanol with expectorant, antitussive, antibacterial, antitumor, and diuretic activities.

Moistens the lung and resolves phlegm — treats cough with difficult-to-expectorate sputum
Descends lung qi and stops cough — applicable across cold, hot, deficiency, and excess cough
Opens the lung and promotes expectoration — relieves wheezing and chest tightness
Secondary: promotes urination (historical use for difficult urination)

Chronic cough from lung deficiency — the classic long-term cough indication
Acute wind-cold cough combined with Jing Jie, Bai Qian
Lung heat cough — combined with Sang Bai Pi, Huang Qin (despite warm nature, the moistening effect prevents drying)
Cough with blood-streaked sputum (hemoptysis) from lung deficiency
Wheezing with phlegm in elderly or deficient patients

Standard dose: 5–10 g; honey-processed (蜜紫菀) preferred for dry or deficiency cough
Raw form for resolving phlegm; honey form for moistening the lung
Generally very safe; suitable for elderly, children, and deficient patients
Use with caution in diarrhea — its moist nature may worsen loose stools
One of the few warm herbs acceptable even in heat-type cough due to its balancing moist quality

Zhi Sou San (止嗽散): Zi Wan, Bai Qian, Bai Bu, Jing Jie, Qian Hu, Jie Geng, Chen Pi, Gan Cao — the definitive versatile cough formula; treats almost any cough presentation
Zi Wan Tang (紫菀汤): Zi Wan, Zhi Mu, Bai Bu, Sha Shen, E Jiao, Chuan Bei Mu — for chronic lung deficiency cough with hemoptysis
Paired with Kuan Dong Hua as the classic ‘Wan Dong’ (菀冬) pair — combined in equal parts as Bai Hua Wan for all types of cough

款冬花 (Kuǎn Dōng Huā) — classic pair: warm and moisten lungs, stop cough; effective for all types of cough regardless of cold or heat (止嗽散 core). 2. 白前 (Bái Qián) + 桔梗 (Jié Gěng) + 荆芥 (Jīng Jiè) — wind invasion cough (止嗽散). 3. 阿胶 (Ē Jiāo) + 麦冬 (Mài Dōng) — lung yin deficiency cough with blood-streaked sputum. 4. 百部 (Bǎi Bù) + 川贝母 (Chuān Bèi Mǔ) — chronic dry cough from lung deficiency. 5. 知母 (Zhī Mǔ) + 桑白皮 (Sāng Bái Pí) — lung heat cough with fever. Source: 神农本草经, 医学心悟 (止嗽散).

saponins
- Expectorant: reduce surface tension of bronchial secretions
- Expectorant: increase mucociliary transport and sputum volume
shionone acts on peripheral cough receptors
- Antitussive: reduces cough reflex sensitivity
Antibacterial
- active against Mycobacterium tuberculosis, Staphylococcus aureus, and E. coli
astin C
- Antitumor: induces apoptosis in Jurkat T-leukemia and MCF-7 breast cancer lines
Bronchodilatory
- relaxes airway smooth muscle via β₂-adrenergic stimulation
saponin fraction
- Mild laxative: promotes intestinal peristalsis

Shen Nong Ben Cao Jing (《神农本草经》): ‘Governs counterflow cough with upward qi, cold-heat bound qi in the chest, eliminates gu toxin and wilting inversion, and calms the five organs.’
Ben Cao Gang Mu (《本草纲目》): ‘Aster Root is acrid, bitter, and slightly warm; enters the Lung channel; moistens the Lung and descends qi, dissolves phlegm and stops cough; treats chronic cough, lung atrophy, expectoration of pus-blood, and Lung channel deficiency heat.’
Ben Cao Bei Yao (《本草备要》): ‘Moistens the Lung and descends qi, dissolves phlegm and stops cough; treats consumptive taxation, cough with expectoration of pus and blood, lung atrophy, lung abscess, and cold-heat bound qi.’