A recent study in Switzerland investigated the occurrence of Chai Hu (Bupleuri Radix) in herbal formulas and whether the prescription pattern reflected its major applications. The classic texts (Shen Nong Ben Cao Jing) lists different indications for Chai Hu but in the modern world, Chai Hu is used to harmonise the Shaoyang (especially with a high dosage of up to 24g), it’s used to assist in spreading the Qi of the liver (wood element needs to expand ) and to raise and lift the Yang Qi. Chai Hu has an upward and outward movement. The season of the wood element is spring.
The Swiss investigation resulted in the findings that Chai Hu was used in mainly 3 formulations:
- Xiao Yao San (Rambling Powder) – a formula to harmonise the Wood and Earth element.
- Jiao Wei Xiao Yao San (augmented Rambling powder) – an addition of two herbs to the basic formula to address heat.
- Chai Hu Shu Gan Tang (Bupleurum powder to spread the liver) – a formula to assist with stagnation of the liver Qi.
In over 50% of these formulations, Chai Hu was combined with Bai Shao (Paoniae Radix, Alba), Dang Gui (Angelica Sinensis, Radix) or Fu Ling (Poria).
Conclusion: Chai Hu was generally prescribed in classic combinations with other herbs and in a medium dosage. Due to the addition of supplementary herbs to classical formulas, its daily dose was often diminished from a high or medium dose to a low dose. This raises the question if Chai Hu would then still exert its desired function of, e.g., moving liver-Qi in these prescriptions.
Xiao Yao San must be one of the most commonly used herbal formulations of our times. It works for many people and works really well. It helps the spleen to relax from the attacks of the liver and being exposed to high levels of stresses and expectations in a very competitive environment, this is what our spleens really just need. An overacting liver on the spleen is one of the most common patterns in our world and hence Xiao Yao San, rambling powder, generally addresses this problem quiet well.
 Chinese herbal medicines Materia Medica, 3rd edition, D Bensky, S Clavey, E Stoeger 2004
Image courtesy of prozac1 at FreeDigitalPhotos.net