Classic TCM Formula: Minor Bupleurum Decoction (小柴胡汤)

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Xiao Chai Hu Tang (Minor Bupleurum Decoction)

Source: Discussion of Cold-induced Disorders (Shang han lun)

Radix Bupleuri (chai hu)   24g

Radix Scutellariae (huang qin)    9g

Rhizoma Pinelliae Ternatae (ban xia)  24g

Rhizoma Zingiberis Officinalis Recens (sheng jiang)  9g

Radix Ginseng (ren shen) 9g

Honey-fried Radix Glycyrrhizae Uralensis (zhi gan cao)      9g

Fructus Zizyphi Jujubae (da zao)  12 pieces



Chai Hu

Chai Hu

The source text advises to decoct the above ingredients in approximately 12 cups of water until 6 cups remain. The ingredients are removed and the strained decoction is further decocted until 3 cups remain.  This is taken warm in three equal doses over the course of one day.

Today usually prepared as a decoction in the usual manner. Two-to-three times the dosage of Radix Codonopsis Pilosulae (dang shen) is commonly substituted for Radix Ginseng (ren shen). Today, most practitioners reduce the dosage of Radix Bupleuri (chai hu) and Rhizoma Pinelliae Ternatae (ban xia) to 12g, honey-fried Radix Glycyrrhizae Uralensis (zhi gan cao) to 6g, and Frucrus Zizyphi Jujubae (da zao) to 4 pieces. Available in prepared form.


Harmonizes and releases lesser yang-stage disorders.


Huang Qin

Huang Qin


Alternating fever and chills, dry throat, bitter or sour taste in the mouth, dizziness, irritability, sensation of fullness in the chest and hypochondria (often experienced as difficulty in taking deep breaths), heartburn, nausea and vomiting, reduced appetite, a thin, white tongue coating, and a wiry pulse.

This is the lesser yang stage of the six stages of disease, or the half-exterior, half-interior aspect of the eight parameters of disease. At this level the struggle between the pathogenic qi, which is trying to penetrate deeper into the body, and the normal qi, which is trying to force it out, is expressed by three major groups of symptoms. The half-exterior aspect is reflected in the alternating chills and fever and the sensation of fullness in the chest and hypochondria due to heat in the lesser yang channels. The half-interior aspect is reflected in the heat rising upward with a bitter or sour taste in the mouth, a dry throat, and dizziness. The third group of symptoms is associated with the Gallbladder, which is the organ that corresponds to the lesser yang. In this pattern, the Gallbladder qi attacks the Stomach, resulting in heartburn, nausea, vomiting, and reduced appetite. The wiry pulse indicates Liver and Gallbladder involvement. Sometimes the pulse is thin, which is indicative of the stage between the greater yang (floating) and yang brightness (overflowing) stages of disease.



Ban Xia

Ban Xia

The chief herb, Radix Bupleuri (chai hu), is the most important herb for venting lesser yang-stage disorders. When combined with the deputy, Radix Scutellariae (huang qin), which drains heat from the Liver and   Gallbladder (the interior aspect of the lesser yang stage), it vents the pathogenic influence and thereby releases Iesser yang stage disorders. Radix Bupleuri (chai hu) also spreads the Liver qi with an ascending, cooling action (contrary to most cooling, which causes things to descend). This combination therefore drains the hear without causing it to sink deeper into the body.

One of the assistants, Rhizoma Pinelliae Ternatae (ban xia), warms and transforms phlegm and turbidity in the middle burner. When combined with another assistant, Rhizoma Zingiberis Officinalis Recens (sheng jiang), it harmonizes the middle burner, directs rebellious qi downward, and stops nausea and vomiting. The remaining assistants, Radix Ginseng (ren shen), honey-fried Radix Glycyrrhizae Uralensis (zhi gan cao), and Fructus Zizyphi jujubae (da zao), support the normal qi and thereby prevent the pathogenic influence from penetrating into the interior. Honey-fried Radix Glycyrrhizae Uralensis (zhi gan cao), and Fructus Zizyphi jujubae (da zao) also moderate the acrid, dry properties of Rhizoma Pinelliae Ternatae (ban xia) and Rhizoma Zingiberis Officinalis Recens (sheng jiang). The combination of Rhizoma Zingiberis Officinalis Recens (sheng jiang) and Fructus Zizyphi jujubae (da zao) mildly regulates the nutritive and protective qi, and assists Radix Bupleuri (chai hu) in releasing the half-exterior aspects of this condition.


Sheng Jiang (ginger root)

Sheng Jiang (ginger root)


In the Discussion of Cold-induced Disorders, the common methods of treating externally-contracted diseases are inducing sweating (to release the exterior) and purging or inducing vomiting (to expel interior accumulations). However, for the condition described above, these approaches are inappropriate. The pathogenic influence is lodged too deeply in the interior to be released by sweating, which would only injure the fluids and the normal qi. Yet the condition is not deep enough to justify purging, which would injure the yin and could lead to palpitations with anxiety. And because there is no excess in the chest, inducing vomiting would injure the yang of the chest and could lead to palpitations. Therefore a different, harmonizing approach is necessary.

This formula, with its many applications, is mentioned over 30 times in Discussion of Cold-induced Disorders and Essentials from the golden Cabinet. Chapter 101 of Discussion of Cold-induced Disorders underscores the wide applicability of this formula. There it states that in patients with injury from cold or wind attach, only one of the symptoms of the Minor Bupleurum Decoction (chai hu tang) pattern is needed to make the diagnosis. Another disorder for which this formula is prescribed in these books is heat entering the chamber of the blood. This condition is characterized by alternating fever and chills, dry throat, and discomfort in the hypochondria in women. This is commonly due to colds contracted after childbirth or during menstruation.

ren shen

ren shen

Clinically, the therapeutic scope of this formula has been greatly expanded over the centuries to include a wide variety of problems associated with the presentation above, but which have not necessarily progressed through the stages of an externally contracted disorder. Today it is thought that any condition which possesses the salient characteristics of this presentation can be regarded as a lesser yang condition. These conditions are not located in a set place in the body and their presentations are typically unpredictable. Modern physicians have used this formula and its modifications in treating a myriad of problems including childhood diarrhea, habitual constipation, renal colic, acute rheumatic fever, malaria, and gastritis from reflux of bile.

There is a large discrepancy between the dosage of Radix Bupleuri (chai hu) prescribed in the source text and that used by most modern practitioners. In  part, this is due to a fear of that herb passed on to later generations by the famous physician and chief architect of the warm-febrile disease school, Ye Tian-Shi. Ye believed that it was a dangerous herb that “plunders the yin,” and should therefore be used sparingly. This is a source of fierce debate today, and many practitioners believe that while a relatively large dosage of the herb is quite safe for most patients, it should be used with caution in patients with yin deficiency.

With the appropriate presentation, this formula may be used in treating such biomedically-defined disorders as upper respiratory tract infection, influenza, bronchitis, pulmonary tuberculosis, epidemic parotitis, jaundice, malaria, acute viral hepatitis, post partum fever, acute pyelonephritis, cholecystitis, lymphadenitis, and intercostal neuralgia.

zhi gan cao

zhi gan cao


This formula has an ascending action which can injure the qi and cause headache, dizziness, and bleeding of the gums if taken long-term. These side-effects can be reduced or eliminated if the formula is prepared according to the directions in the source text. For the same reason, unless considerably modified, it is contraindicated in patients with excess above and deficiency below, Liver fire, or bleeding of the gums. Use with caution in cases of ascendant Liver yang, hypertension, or vomiting of blood due to yin deficiency. Patients with relatively weak normal qi may experience fever and chills while taking this formula because the pathogenic influence is vented from the lesser yang stage via the greater yang.



da zao

da zao

  • For pronounced thirst, omit Rhizoma Pinelliae Ternatae (ban xia) and add Radix Trichosanthis Kirilowii (tian hua fen).

  • For abdominal pain, omit Radix Scutellariae (huang qin) and add Radix Paeoniae Lactiflorae (bai shao).

  • For rough, scanty, dark, and painful urination, add Herba Lysimachiae (jin qian cao) and Herba Hedyotidis Diffusae (bai hua she she cao).

  • For fever, aversion to wind, headache, a stifling sensation in the chest, constipation, loss of appetite, dark urine, irritability, thirst, a yellow tongue coating, and a tight pulse, add Semen Cannabis Sativae (huo ma ren) and Fructus Immaturus  Citri Aurantii (zhi shi).

  • For fever, coughing of yellow sputum, and chest pain, add Radix Platycodi Grandiflori (jie geng), Fructus Trichosanthis (gua lou) and Buibus Fritillariae Cirrhosae (chuan bei mu).

  • For malarial disorders, add Herba Artemisiae Annuae (qing hao) and Radix Dichroae Febrifugae (chang shan).

  • For vertigo, add Flos Chrysanthemi Morifolii (ju hua), Ramulus cum Uncis Uncariae (gou teng) and Semen Cassiae (jue ming zi).

  • For coughs that are more severe around midnight, alternating fever and chills, and a bitter taste in the mouth, add Rhizoma Zingiberis Officinalis (gan jiang), Herba cum Radice Asari (xi xin) and Fructus Schisandrae Chinensis (wu wei zi). This application was pioneered by the Qing-dynasty physician, Chen Xiu-Yuan, who also used it to treat coughs that did not respond to other treatment.

  • For urinary tract infection with chills, fever and urgent, frequent urination, take with Six-Ingredient Pill with Rehmannia (liu wei di huang wan). This was developed by the famous twentieth- century physician, Yue Mei-Zhong.

(Chinese Herbal Medicine Formulas and Strategies, Eastland Press, 1990)