Leonorus (yi mu cao)

What is leonorus? What is it used for?

Leonorus (better known as motherwort) originated in central Eurasia, but is now found throughout most of the world’s temperate zones, primarily as a garden plant. It is part of the mint family.

Different varieties of leonorus are found worldwide; the most well-known versions are L. cardiaca, L. sibiricus and L. heterophyllus. The plant consists of a long stem, with pointed green leaves, red and white flowers, and an exceptionally bad odor. The leaves and plants are used in herbal preparations.

In traditional Chinese medicine, leonorus is considered bitter and pungent, and has a slightly cold disposition. It affects the Liver and Pericardium meridians. It is used to promote blood circulation and clear blood clots, treat menstrual problems and reproductive disorders, and lower blood pressure; some practitioners have used leonorus as a sedative and to alleviate heart palpitations.

How much leonorus should I take?

Most practitioners recommend a preparation of 4.5 grams of cut leonorus steeped in 1/2 to 3/4 cups of water. Up to three cups of leonorus tea may be consumed daily. Alternatively, a leonorus tincture (2-4 ml) may be taken three times per day.

What forms of leonorus are available?

Fresh cut leonorus may be found at some herbal shops and specialty stores. Leonorus tinctures and powders are also available.

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

The American Herbal Products Association has given leonorus a class 2B rating, meaning that it should not be taken by women who are pregnant, as large amounts of the herb may cause uterine contraction and lead to a potential miscarriage. In addition, some evidence exists that motherwort extract may cause diarrhea and/or stomach irritation.

As of this writing, there are no well-known drug interactions with leonorus. As always, make sure to consult with a licensed, qualified health care provider before taking leonorus or any other herbal remedy or dietary supplement.

References

• Bensky D, Gamble A, Kaptchuk T. Chinese Herbal Medicine Materia Medica, revised edition. Seattle: Eastland Press, 1993, pp. 273-74.
• Blumenthal M (ed.) The Complete German Commission E Monographs. Therapeutic Guide to Herbal Medicines. Newton, MA: Integrative Medicine Communications, 1998, p. 172.
• Blumenthal M (ed.) Herbal Medicine: Expanded Commission E Monographs. Newton, MA: Integrative Medical Communications, 2000, pp. 267-69.
• Foster S. Herbal Renaissance. Layton, UT: Gibbs Smith, 1993, pp. 151-52.
• McGuffin M, Hobbs C, Upton R (eds.) American Herbal Products Association’s Botanical Safety Handbook. Boca Raton, FL: CRC Press, 1997, pp. 68-69.