Nature: bitter, slightly acrid, cold
Enters: Lung, Large Intestine
Actions: Resolves phlegm; clears Lung heat; stops coughing, relieves wheezing.
• Lung heat: cough with difficult breathing.
• Lung deficiency: prolonged cough.
• Bleeding hemorrhoids.
• Hypertension with lightheadedness and flushing: lowers blood pressure an average of 15 mm Hg diastolic.
• Very bitter. May make some patients vomit. Gua lou is often substituted.
• Honey-frying this herb makes it less cold and bitter, and reduces the side effects of nausea and vomiting.
• Contains aristolochic acid [only slightly soluble in water – Merck Index], which has been associated with renal damage when misused. This herb is likely obsolete in the United States due to legal restrictions on its import and use.
Hsu: Strong expectorant (stronger than ammonium chloride).