Xiao Yao San: ingredients, dose, uses, and side effects
Xiao Yao San, the Rambling Powder, recorded in the Song-dynasty Taiping Huimin Heji Ju Fang, is the formula for Liver qi stagnation that has begun to consume the Blood and weaken the Spleen. It soothes the Liver, nourishes the Blood, and fortifies the Spleen in one prescription, and it is the most widely dispensed formula in modern practice for the person who is irritable and tired at once: distension under the ribs, sighing, moodiness, fatigue, a poor appetite, irregular or painful periods with breast tenderness before them, a pale-red tongue, and a pulse that is wiry and thin. The name describes the result: qi that wanders freely again.
Ingredients and their logic
| Herb | Pharmaceutical name | Role | Dose in decoction |
|---|---|---|---|
| Chai Hu | Bupleuri Radix | Chief: spreads the Liver, lifts constrained qi | 6 to 9 grams |
| Dang Gui | Angelicae sinensis Radix | Deputy: nourishes and moves the Blood | 9 grams |
| Bai Shao | Paeoniae Radix alba | Deputy: nourishes Liver Blood, softens the Liver | 9 to 12 grams |
| Bai Zhu | Atractylodis macrocephalae Rhizoma | Assistant: fortifies the Spleen, dries damp | 9 grams |
| Fu Ling | Poria | Assistant: fortifies the Spleen, leaches damp | 9 to 15 grams |
| Zhi Gan Cao | Glycyrrhizae Radix praeparata | Assistant and envoy: tonifies the middle, harmonises | 3 to 6 grams |
| Bo He | Menthae Herba | Envoy: helps Chai Hu disperse, added at the end | 3 grams |
| Wei Jiang | Zingiberis Rhizoma recens, roasted | Envoy: warms and harmonises the Stomach | 3 grams |
The Ju Fang gives it as a coarse powder, boiled by the dose with a piece of roasted ginger and a little mint; today it is decocted from the whole, with Bo He put in for the last few minutes so that its aroma is not boiled off. Chai Hu is chief because the disorder is the Liver's failure to course freely. Dang Gui and Bai Shao are deputies because the Liver is yin in substance and yang in function: it cannot course smoothly when it is short of the Blood it stores, and a Chai Hu given without Blood herbs dries and lifts too hard. Bai Zhu, Fu Ling, and Gan Cao are Si Jun Zi Tang without its ginseng, placed here on the principle the Jingui Yaolue states at its opening, that when the Liver is diseased the Spleen will be invaded next, so the Spleen is fortified first.
Variants
Jia Wei Xiao Yao San, also Dan Zhi Xiao Yao San, attributed to the Ming physician Xue Ji, adds Mu Dan Pi, moutan bark, 6 to 9 grams, and Zhi Zi, gardenia fruit, 6 to 9 grams. It is the formula when stagnation has turned to heat: irritability that flares, a hot face, hot flushes, early and heavy periods, a dry mouth, a red tongue with a yellow coat, and a wiry rapid pulse. Hei Xiao Yao San adds Shu Di Huang, prepared rehmannia root, for deeper Blood deficiency with dizziness and a scanty period.
Doses: decoction, pill, granule
The decoction doses above make one day's prescription, boiled twice and drunk in two portions. Xiao Yao Wan, the pill, is the same formula in the Chinese Pharmacopoeia's water-pill form at 6 to 9 grams a dose, once or twice a day. The small concentrated pills sold in bottles follow the count printed by the maker, and granule extracts follow the maker's stated equivalence to the decoction. The pill acts more slowly; the decoction is chosen where the case is acute or the formula needs modifying.
Uses
The formula is used wherever the pattern is found: premenstrual irritability and breast distension, irregular cycles, painful periods with Blood deficiency, menopausal moodiness with fatigue, low mood with a tight chest and sighing, headaches at the temples that follow stress, bowels that alternate between loose and bound as the Liver invades the Spleen. It suits the person who is tense and tired together; the person who is only tense, with a wiry forceful pulse, takes Chai Hu Shu Gan San, and the person who is only tired takes the Spleen formulas.
Side effects and when it is not used
The formula is gentle, and its unwanted effects are the ones its herbs predict. Dang Gui moistens the bowels and can loosen the stool; in a person already loose it is reduced or Bai Zhu increased. Chai Hu rises and disperses, and the warm-disease school warns that it plunders Liver yin: in Liver yin deficiency with heat, with dizziness, tinnitus, a red peeled tongue, and a thin rapid pulse, the formula aggravates and Yi Guan Jian is used instead. It is not the formula for Liver fire with a red face and eyes, a bitter taste, and a yellow coat, which calls for Long Dan Xie Gan Tang, nor for pure yin deficiency without stagnation. It is used with care in pregnancy because of Dang Gui and Chai Hu. Gan Cao is present in a small amount, and with long use liquorice raises blood pressure and lowers potassium and adds to the effect of warfarin.
Not medical advice.