Juncus (deng xin cao)

What is juncus? What is it used for?

Juncus is one of the most unusual looking herbs in traditional Chinese medicine. The English translation of deng xin cao means "lamp wick herb," which is what the herb resembles in appearance after being dried.

There are more than 20 known species of juncus, many of which grow in lakes, ponds and marshlands. Only the pith, the soft, sponge-like cylindrical center of the plant is used in herbal remedies, however.

Juncus has sweet, bland and slightly cool properties, according to the precepts of traditional Chinese medicine, and is associated with the Heart, Lung and Small Intestine meridians. It acts as a diuretic, and is often used to treat dysuria and other urinary conditions. In addition, juncus helps treat edema. Juncus is often used as a sedative to promote sleep and reduce the incidence of irritability and insomnia in both adults and children.

The type of juncus being used will depend on the condition being treated. Unprocessed juncus is used to regulate the flow of water in the body and promote urination. Charred juncus acts as a sedative.

How much juncus should I take?

The typical dosage of juncus is between 3 and 5 grams of pith, added to hot water and drunk as a decoction. Powdered juncus can also be applied topically to help relieve pain and swelling.

What forms of juncus are available?

Dried juncus can be found at some herbal shops and Asian markets. Juncus is also available as a powder, pill, capsule and tablet. Some formulas that promote relaxation also include juncus as an ingredient.

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

Juncus should not be administered to patients with urinary incontinence, or those who have been diagnosed with deficiency of the middle jiao. As of this writing, there are no known drug interactions associated with juncus. As always, make sure to consult with a licensed health care provider before taking juncus or any other herbal remedy or dietary supplement.

References

• Chen JK, Chen TT. Chinese Medical Herbology and Pharmacology. City of Industry, CA: Art of Medicine Press, 2004, pp. 399-400.
• Collins BS, Sharitz RR, Coughlin DP. Elemental composition of native wetland plants in constructed mesocosm treatment wetlands. Bioresour Technol May 2005;96(8):937-48.
• Corsaro MM, Della Greca M, Fiorentino A, et al. Cycloartane glucosides from juncus effusus. Phytochemistry September 1994;37(2):515-9.
• Della Greca M, Fiorentino A, Isidori M, et al. Phenanthrenoids from the wetland juncus acutus. Phytochemistry July 2002;60(6):633-8.
• Saltzman M, Saltzman M. Chinese Herbal Medicine Materia Medica Study Guide. Brookline, MA: Complementary Medicine Press, 1992.