Si Ni San – an example of how we think about formulas

Si Ni San   四逆散   (Frigid Extremities Powder)

Discussion:
Si Ni San (Frigid Extremities Powder) was first mentioned in the Shang Han Lun, or Discussion of Cold Induced Disorders, where its use is confined to the treatment of cold extremities from shao yin syndrome. Here, it is due to yang collapse, where heat has entered the interior where it constrains yang qi, leading to a warm body, but with yang failing to spread to the extremities, causing cold fingers and toes. This is referred to as yang or hot type collapse, yang jue (阳厥). Yin or cold type collapse, yin jue, is where the entire area distal to the elbow or knee may be cold. In this case, it is the tips of the fingers and toes only. This is a condition of constraint and stagnation of the qi mechanism. Its primary focus is to regulate the qi, by clearing heat and releasing constraint. It has come to be used as well for liver qi constraint, particularly where it is invading the stomach.

Later generations value it as a versatile base formula that can be used as the core of other prescriptions, for example, Chai Hu Shu Gan San (Bupleurum Powder to Spread the Liver) and Xue Fu Zhu Yu Tang (Drive Out Stasis in the Mansion of Blood Decoction).

Original citation;
When in lesser yin1 disease [there is] counterflow cold of the limbs, the person may cough, or have palpitations, or inhibited urination, or pain in the abdomen, or diarrhea with rectal heaviness; Si Ni San (Counterflow Cold Powder) governs. (Shang Han Lun, Line 318). Translation by Craig Mitchell, et al.

Commentaries on the original citation;
This is shao yang reverting yin; thus the sovereign is Chai Hu, which courses the liver yang. The minister is Bai Shao, which drains the liver yin. The assistant is Gan Cao, which moderates the liver qi. The courier is Zhi Shi, which breaks liver counterflow. When these three agents meet Chai Hu, they are able to penetrate the yang of the shao yang in the exterior. They penetrate the yin of the reverting yin in the interior. Then the coursing and draining nature of the liver and gallbladder succeeds and the reversal is unblocked. (Yi Zong Jin Jian: Wu Qian et al.)

This formula uses the sour and cold [nature] of Bai Shao to penetrate yin, the sweet neutral [nature] of Gan Cao to harmonize the center, the aromatic [nature] of Chai Hu to course yang, and the bitter cold [nature] of Zhi Shi to resolve binds. Once the evil resolves, the qi is harmonious, and the yang is outthrust, the counterflow cold will spontaneously resolve. (Han Fang Jian Yi)

Discussion of ingredients:
This formula appears organized around the Nei Jing concept that treatment of heat excess can accomplished with sweet, bitter medicinals that effuse, as well as sour medicinals that contract. As illustrated by the bitterness of zhi shi drains interior heat; the sweetness of gan cao moderates counterflow qi; the sourness of bai shao contracts the yin qi; and the bitterness of chai hu effuses and disperses the bound and depressed heat and clears exterior heat

Chai Hu, the chief, courses and normalizes the qi dynamic, and vents heat, upbears and effuses clear yang and raises clear (lucid) qi to assist the function of the spleen
Zhi Shi, the assistant, moves qi and disperses bind, drains stagnation with bitterness from the middle jiao and thereby aids the transformation and transportation functions of the spleen
Chai Hu has an ascending action, Zhi Shi a descending action together aiding in releasing constraint and regulating the qi mechanism
Bai Shao, the support, nourishes the liver, and the blood, and constrains/protects the yin. Depressed heat can damage the yin. It contains, where Chai Hu disperses, so it is an important medicinal to spread liver qi, while protecting the liver yin
Zhi gan cao, the courier, relaxes tension, strengthens the spleen, harmonises the different actions of the other medicinals
Zhi Gan Cao and Bai Shao, emolliate the liver and harmonise the spleen thereby softening and moderating abdominal pain

Associated formulas:

Chai hu shu gan san (Bupleurum and cyperus formula or Bupleurum powder to spread the liver)
A well known modification of Si Ni San. It is from the Jing Yue Quan Shu or “Collected works of Jing Yue”. This is a collection of the works of the influential Zhang Jing Yue.

Original citation
“For patients with an unresolved exterior penetration and simultaneous qi counterflow and hypochdriac pain, chai hu shu gan san governs.”

Commentary. A later text refers to it;
“Chai hu shu gan san treats anger and fire damaging the liver, left side hypochondriac pain, [and[ blood that is depressed in the upper body.”

Discussion of Ingredients:
Chai Hu upbears, disperses, courses and regulate the liver and resolves depression, relieves constraint and stagnation of the qi, and vents heat
Chen pi rectifies the qi and opens the stomach
Zhi ke loosens the middle jiao, resolves distention
Xiang fu moves qi and courses the liver
The above 3 rectify qi
Bai Shao nourishes and emolliates the liver and protects the yin
Chuan xiong moves blood and disperses depression
The above 2 nourish the blood
Zhi gan cao relaxes tension, strengthens the spleen, harmonizes the actions of the other medicinals

Xiao yao san (Bupleurum and dang gui formula or Rambling powder)
The name of the formula is derived from a chapter title in a book of writings attributed to the Daoist, Zhuang Zi, “Rambling Without a Destination.” It has also been translated as “Free and Easy Wanderer,” perhaps based on stories in the chapter of overcoming limited worldviews. The formula has the action of establishing the happy going and free flowing nature of liver qi, which encourages a open minded, free and flexible approach to life.

It first appeared in the influential 11th century compendium, Tai Ping Hui Min He Ji Ju Fang, (Imperial Grace Formulary of the Tai Ping Era). It was commissioned by the then Song dynasty ministry of health. Rather than listing all the important formulas, it was a more concise compendia than others, designed specifically for clinicians. It focuses on 800 formulas that were considered important by most eminent physicians of the time.

Xiao Yao San is a modification of the Shang Han Lun formula, Si Ni San. Along with Xiao Chai Hu Tang, it is an important representative formula of the harmonizing method.

Xiao Yao San is safe to use over long periods of time. The name of the formula alludes to the action of xiao, melting the signs of stasis, without harming the blood, much like the sun melts ice without diminishing the essence of water; it further refers to the effect of yao, moving the qi without dispersing it, like an oar stirs up ripples in the water without harming its basic substance.

Discussion of ingredients:
The chief herb Chai Hu relieves liver qi constraint
The deputies Dang Gui and Bai Shao together nourish the blood and soften the liver
Dang Gui being slightly aromatic also effects the qi of the blood while it helps with blood deficiency
The assistants Bai Zhu, Fu Ling strengthen the spleen
The other assistants Zhi Gan Cao tonifies the spleen and when combined with Bai Shao relieves spasms
The envoy, Wei Jiang, roasted ginger, harmonises the stomach and prevents counterflow of qi
The other envoy, Bo He when used in small doses, helps Chai Hu relieve liver qi constraint and disperses heat form constraint