Herbs & Botanicals
Pyrrosia Leaf (shi wei)
What is pyrrosia leaf? What is it used for?
Pyrrosia is a type of perennial, evergreen herb. It grows throughout China, with thin green leaves. The leaves are used in herbal remedies. They are gathered throughout the year, then cleaned, dried in the sun and cut into small pieces. Pyrrosia leaf contains a variety of chemical substances, including saponins, tannins, fumaric acid, fructose, and glucose.
According to the principles of traditional Chinese medicine, pyrrosia leaf has bitter, sweet and slightly cold properties, and is associated with the Bladder and Lung meridians. Its main functions are to clear damp heat and expel phlegm. The leaves have antitussive, expectorant and antiviral properties. Among the conditions pyrrosia leaf treats are bronchitis, asthma, congestion, coughs, kidney stones and gallstones. It also helps to regulate the frequency of urination.
How much pyrrosia leaf should I take?
The typical daily dose of pyrrosia leaf is between 5 and 10 grams, decocted in water for oral use. Larger doses (15-30 grams) may be administered in severe cases.
What forms of pyrrosia leaf are available?
Dried, sliced pyrrosia leaf is the most common form available; it can be found at many Asian markets and herbal shops. Some vendors also sell pyrrosia leaf powders, pills and capsules. Pyrrosia leaf is also included in some larger herbal formulas for urinary conditions.
What can happen if I take too much pyrrosia leaf? Are there any interactions I should be aware of? What precautions should I take?
Large doses of pyrrosia leaf may cause anxiety and dizziness in sensitive individuals. If this occurs, discontinue use. As of this writing, there are no known drug interactions associated with pyrrosia leaf. As always, make sure to consult with a licensed health care provider before taking pyrrosia leaf or any other herbal remedy or dietary supplement.
- Chen JK, Chen TT. Chinese Medical Herbology and Pharmacology. City of Industry, CA: Art of Medicine Press, 2004, pp. 417-418.
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