Arnebia (zi cao or ying zi cao)

What is arnebia? What is it used for?

Arnebia is a perennial herb that goes by many names, including lithosperm and purple gromwell. It gets the name "purple gromwell" because of its root, which turns purple when dried. It is indigenous to Korea, China and Japan, and can reach a height of more than three feet.

The typical arnebia consists of a thin, tube-like structure, with alternately spaced leaves, white flowers and a glossy, nut-like fruit, which is also white or light gray in color. The root is used medicinally. Arnebia is usually harvested when the plant reaches three years of age. The roots are collected in the spring or autumn, cleaned, cut in slices, then dried.

In traditional Chinese medicine, arnebia is associated with the Heart and Liver meridians, and has sweet and cold properties. Its functions are to cool and invigorate the blood, release toxins, and moisten the intestines. In the Western setting, arnebia can be used to treat constipation, reduce swelling, and care for skin rashes and eczema. The roots contain a variety of active ingredients, including several short-chain fatty acids, alkaloids, and derivatives of caffeic acid.

How much arnebia should I take?

Traditionally, the recommended dose of arnebia was between 3 and 10 grams, infused with water and taken as a tea. However, most practitioners now recommend against taking arnebia internally. It is still used occasionally to treat skin conditions, however.

What forms of arnebia are available?

Dried slices of arnebia root can still be found at some herbal shops and specialty stores. Powdered arnebia root is also available in some locations.

What can happen if I take too much arnebia? Are there any interactions I should be aware of? What precautions should I take?

Some of the alkaloids found in arnebia root have been associated with liver dysfunction, and may even cause cancer. As a result, it should never be taken by patients with liver problems, or who are on anti-cancer medications. It should also not be taken by people who have weakness of the spleen accompanied by diarrhea. As always, make sure to consult with a licensed health care provider before taking arnebia or any other herbal remedy or dietary supplement.


  • Duke JA, Ayensu ES. Medicinal Plants of China. Reference Publications, Inc., 1985. ISBN # 0-917256-20-4.
  • Gruenwald J, Brendler T, Jaenicke C (eds.) PDR for Herbal Medicines.
  • Montvale, NJ: Medical Economics Company, 2000, pp. 619-620. Yang S. The Heart and Essence of Danxi's Methods of Treatment. Boulder, CO: Blue Poppy Press, 1993.
  • Yeung HC. Handbook of Chinese Herbs and Formulas. Los Angeles: Institute of Chinese Medicine, 1985.
  • Yinyan G, Fengshan G. Treatment of 72 cases of allergic rhinitis with danggui yinzi. Sichuan Journal of Chinese Medicine 1999;17(2):48.