Magnolia Bark (hou po)

Magnolia bark comes from the magnolia tree, a deciduous arbor that grows in the Sichuan, Hubei and Zhejiang provinces of China. The tree is often used as a type of ornamental for gardens, and is an important source of timber, with green leaves and fragrant flowers that vary in color from white to purple.

The bark is harvested first by being peeled from the tree, then dried, boiled (until the internal surface of the bark turns a dark red or brownish gray), steamed until soft, and rolled into cylindrical pieces. At that point, the bark is again dried and prepared with ginger juice for later use.

In traditional Chinese medicine, magnolia bark has bitter, pungent and warm properties, and is associated with the Liver, Lung, Spleen and Stomach meridians. Traditionally, it has been used to treat asthma, coughs and abdominal problems. It is often used with other herbs, such as atractylodes, tangerine peel, and apricot kernels.

How much magnolia bark should I take?

The typical dosage of magnolia bark is between 3 and 10 grams, boiled in water for oral use as a decoction.

What forms of magnolia bark are available?

Dried, rolled magnolia bark can be found at many herbal shops and specialty stores. However, magnolia bark does not last long in storage, so stocks of the bark need to be replenished rather often. Magnolia bark is also incorporated into larger herbal formulas. Extracts of magnolia bark are available in capsule and tincture form.

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

Magnolia bark has been given a class 2B rating by the American Herbal Products Association, which means that it should not be used by women who are pregnant. In addition, magnolia bark contains a compound called magnocurarine, which has a sedative effect; large amounts can reduce blood pressure. As of this writing, there are no known drug interactions associated with magnolia bark. As always, make sure to consult with a licensed health care provider before taking magnolia bark or any other herbal remedy or dietary supplement.

References

• Bang KH, et al. Antifungal activity of magnolol and honokiol. Archives of Pharmaceutical Research 2000;23(1):46-49.
• Hong-Yen H, et al. Oriental Materia Medica: A Concise Guide. Long Beach, CA: Oriental Healing Arts Institute, 1986.
• Kuribara H, et al. The anxiolytic effect of two oriental herbal drugs in Japan attributed to honokiol from magnolia bark. Journal of Pharmacy and Pharmacology 2000;52(11):1425-1429.
• McGuffin M, Hobbs C, Upton R, et al. (eds.) American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, 1997, pp. 72-73.
• Yang SZ (translator). The Divine Farmer's Materia Medica. Boulder, CO: Blue Poppy Press, 1998.