Cynanchum Root

Traditional Use

Primary Actions

• Directs Lung Qi downward and transforms phlegm - Bai Qian is a core herb for cough, dyspnea, chest fullness, and noisy phlegm when the Lung fails to descend.
• Relieves cough in both cold-phlegm and mixed obstruction patterns - its action is broad enough to appear in formulas for new or chronic cough, especially when phlegm is prominent.
• Opens the chest and eases labored breathing - by restoring the descending function of Lung Qi, it helps reduce a sense of blockage in the chest and difficulty exhaling.

Secondary Actions

• Bai Qian is valued because it is neither extremely drying nor extremely cold, making it more flexible than harsher phlegm-transforming herbs.
• Honey-processed Bai Qian is considered milder and is often chosen when lingering dry cough or deficiency complicates the phlegm pattern.

Classic Formulas

• Zhi Sou San - Bai Qian works with Jing Jie and Jie Geng to stop lingering cough after an exterior pathogen has not fully resolved.
• Bai Qian Wan - a traditional pairing with Lung-draining herbs such as Sang Bai Pi and Ting Li Zi for cough and dyspnea with heat or retained phlegm.
• Bai Qian with Su Zi, Ban Xia, and Bai Jie Zi - a common cold-phlegm strategy for chest fullness, cough, and difficult expectoration.

Classical References

• Traditional sources describe Bai Qian as acrid, bitter, and slightly warm, entering the Lung to descend Qi, transform phlegm, stop cough, and relieve dyspnea.
• The herb is repeatedly praised for handling cough with profuse phlegm regardless of whether the presentation leans somewhat cold or somewhat warm, as long as phlegm obstruction is central.
• Older cautions note that Bai Qian can irritate the Stomach and should be used carefully in patients with weak digestion or a tendency to bleeding.