Discover the Power of Plants
← Back to the Herbal Library
Botanical illustration of Aster Root
MedicinalSourced entry

Aster Root

Aster tataricus

Zi wan, the soft purple root of Aster tataricus, a classic Chinese, Japanese and Korean remedy to moisten the lungs and relieve cough and phlegm.

What is Aster Root?

Plant family
Asteraceae, the daisy family
Parts used
The soft purple roots and rhizome, raw or honey-fried
Where it grows
China, Korea, Japan, eastern Siberia and the northern United States
Genus
Aster
Species
tataricus

Also called

Asteris Radix

Traditional names

Zi Wan, Ziwan

Traditionally used for

  • Cough and phlegm (traditional)
  • Asthma (traditional)

Traditionally described as

  • Eased coughs (in animal studies)

Health topics

Where Aster Root appears in symptom search, and why. Being listed doesn't mean it's a proven treatment.

  • Cough

    A classic Chinese, Japanese and Korean cough and phlegm remedy. Not tested on its own in trials; it has some liver toxicity.

  • Liver Safety Warnings

    Reported to have some liver toxicity.

Traditions that use it

  • Traditional Chinese Medicine

    Called zi wan ("purple, soft"); recorded in the Shennong Herbal Classic as a lung medicine to moisten the lungs and relieve cough and phlegm.

Safety

Toxicity testing

  • Aster root has some liver toxicity. Its cyclic peptides (astins) resemble a known liver-damaging compound, and its saponins can damage red blood cells. Toxicity studies are few; processing and combining it with other herbs are thought to reduce toxicity.[1]

What does the research say?

Traditional use

These are traditional uses, not proven treatments.

  • Zi wan is named for its soft, purple roots. Its use goes back to the Shennong Herbal Classic, where it's an important lung medicine that moistens the lungs and relieves cough and phlegm. It's also used for coughs in Japanese Kampo medicine and for coughs and asthma in traditional Korean medicine. The root is often honey-fried, which changes its chemistry.[1]

Laboratory & animal research

Lab and animal results show what might be worth studying in people. They don't show that the herb has these effects in humans.

  • In lab and animal studies, aster root eased coughs and helped clear phlegm, may help reduce inflammation, relaxed the airways, helped acute lung injury, slowed tumours and reduced bone loss. These haven't been confirmed in people.[1]

In short

Reported to have some liver toxicity.

Sources

  1. [1] Aster tataricus L. f.: a review on the botany, phytochemistry, ethnopharmacology, pharmacology, toxicology and comprehensive utilization · DOI: 10.3389/fphar.2025.1581505Peer-reviewed study

This information is educational and traditional in nature, and is not a substitute for professional medical advice.