Understanding formulas that course the liver qi
Understanding formulas that course the liver qi
A variety of formulas used in Chinese medicine focus on coursing liver qi or regulating wood and earth. Regulating wood and earth can be considered as a method of harmonizing, and formulas such as Si Ni San, Tong Xie Yao Fang, and Xiao Yao San are representative of this approach. Other formulas, such as Chai Hu Shu Gan San, are particularly suited to repletion patterns and tend to primarily course liver qi instead of simultaneously coursing wood and supplementing earth.
With the “Shu Gan” formulas, we find both Chai Hu Shu Gan San (Bupleurum Liver-Coursing Powder) and Shu Gan Tang (Liver-Soothing Decoction). These two classical formulas sound similar in Pinyin and both formulas utilize Chai Hu and other medicinals to course the liver qi. What is the difference between these two formulas?
The words “shu” in these two formula names actually refers to two different characters, though in this context their meaning is synonymous. The “shu gan” in Chai Hu Shu Gan San is translated as “liver-coursing” while the “shu gan” in Shu Gan Tang is translated as “liver-soothing.” These two words have different spectrums of usage in Chinese medicine. For example, one shu is used for “coursing wind” (shu feng) while the other is used for “soothing the sinews” (shu jin). (Pinyin is inherently limiting and occasionally confusing because the Chinese language has many words with the same sound but different characters.) Regardless, in the context of rectifying liver qi, the meaning of both “shu gan” phrases is the fundamentally the same.
The formula Chai Hu Shu Gan San is a derivative of the formula Si Ni San (Counterflow Cold Powder). Si Ni San is one of Chinese medicine’s first formulas for regulating wood and earth, and it remains a fundamental base formula for treating binding depression of liver qi. Si Ni San theory is at the root of both Xiao Yao San (Free Wanderer Powder) and Chai Hu Shu Gan San (Bupleurum Liver-Coursing Powder). If supplementing medicinals are added to Si Ni San to bank up earth, the formula moves in the direction of Xiao Yao San. If one instead adds Xiang Fu (Cyperi Rhizoma) and Chuan Xiong (Chuanxiong Rhizoma) to strengthen the liver-coursing effect, the formula moves in the direction of Chai Hu Shu Gan San.
Chai Hu Shu Gan San is an important representative formula for treating binding depression of liver qi. It contains multiple key pairings of herbs that form the core structure of many related formulas. For example, the pairing of Chai Hu and Bai Shao helps to provide a balance between supplementing and coursing; Bai Shao’s constraining, nourishing nature controls Chai Hu’s tendency to be too outthrusting and drying. This pair is found in Si Ni San, as is the pairing of Chai Hu with Zhi Ke (or Zhi Shi). Chai Hu moves qi upward while Zhi Ke moves qi downward, giving the formula a greater ability to systemically move qi. The pairing of Bai Shao and Gan Cao from Si Ni San and Chai Hu Shu Gan San is also an important pair, and Bai Shao and Gan Cao together relax tension and relieve pain. Chai Hu Shu Gan San is also famous because it illustrates the combination of Chai Hu with Xiang Fu, which have a mutually supportive action in terms of coursing liver qi. Chuan Xiong is added because it has an acrid nature and a qi-moving action; many people overlook Chuan Xiong’s ability to move qi because it is classified as a blood-moving medicinal, but its qi-moving ability is essential in this application.
Chai Hu Shu Gan San was originally recorded in the Jing-Yue Quan Shu (Jing-Yue’s Complete Compendium) in 1624 CE. The formula Shu Gan Tang was created in the same era, by a physician named Gong Ding-Xian in his book Wan Bing Hui Chun (Returning Spring to the Myriad Diseases) in 1587. While Chai Hu Shu Gan San is primarily a formula that is used for coursing the liver to treat qi stagnation, Shu Gan Tang is a formula that courses the liver while also quickening the blood and clearing heat.
Shu Gan Tang starts with the same combination of Bai Shao, Chai Hu, and Zhi Ke that we find in Si Ni San and Chai Hu Shu Gan San. However, Shu Gan Tang adds the liver-coursing medicinal Qing Pi whereas Chai Hu Shu Gan San uses Xiang Fu. Chai Hu Shu Gan San primarily moves qi and only secondarily moves blood (specifically via Chuan Xiong and generally via the fact that moving qi encourages the movement of blood). However, Shu Gan Tang has a much stronger blood-quickening action because it contains Chuan Xiong in conjunction with Tao Ren, Hong Hua, and Dang Gui. This group of blood-quickening medicinals makes Shu Gan Tang similar to Tao Hong Si Wu Tang.
Thus, Shu Gan Tang has a stronger ability to move blood in comparison with Chai Hu Shu Gan Tang, which more purely focuses on moving qi. Additionally, Shu Gan Tang uses the medicinal Huang Lian, which in this application has been processed by dry stir-frying the Huang Lian with Wu Zhu Yu. Wu Zhu Yu is hot and acrid, and tends to enter the liver channel. Huang Lian also enters the liver channel but it is bitter and cold. When Huang Lian is stir-fried with Wu Zhu Yu, its temperature is moderated and its ability to target the liver is strengthened (this is not unlike the theory behind the formula Zuo Jin Wan, which contains just these two herbs together). The presence of Wu Zhu Yu-processed Huang Lian allows the formula to have an additional action of clearing heat, which is commonly formed when qi stagnation persists over time.
Each of these formulas has its own niche, and the patterns that both of these formulas treat are incredibly common in clinic.