Xiao Chai Hu Tang
Star小柴胡汤 (Minor Bupleurum Decoction)
Source: Shang Han Lun — Zhang Zhongjing (Han, 220)
Last updated August 30, 2026
Description
Xiao Chai Hu Tang (Minor Bupleurum Decoction) is one of the most studied and widely used classical formulas, treating Shao Yang syndrome — when disease is neither on the exterior nor fully interior. It harmonizes and releases the Shao Yang, balances Liver-Gallbladder and Spleen-Stomach, and is the basis for numerous modern clinical applications in hepatology, immunology, and respiratory medicine.
Composition
| Herb | Amount | % | Role | Function |
|---|---|---|---|---|
| Chai Hu | 24g | 29.63% | Jun (Chief) | Releases Shao Yang pathogen, harmonizes exterior-interior, spreads Liver Qi. |
| Huang Qin | 9g | 11.11% | Chen (Deputy) | Clears heat from Shao Yang, eliminates Gallbladder heat. |
| Ban Xia | 9g | 11.11% | Zuo (Assistant) | Harmonizes Stomach, descends rebellious Qi, stops vomiting. |
| Ren Shen | 9g | 11.11% | Zuo (Assistant) | Tonifies Spleen Qi, prevents pathogen entering interior. |
| Gan Cao | 9g | 11.11% | Zuo (Assistant) | Tonifies Qi, harmonizes all herbs. |
| Sheng Jiang | 9g | 11.11% | Zuo (Assistant) | Harmonizes Stomach, assists Ban Xia, releases exterior. |
| Da Zao | 12g | 14.81% | Zuo (Assistant) | Tonifies Spleen Qi and Blood, harmonizes Ying Qi. |
Total weight: 96g
Dui Yao — Core Herb Pairs
The classical two-herb combinations at the heart of this formula, as recorded on the herbs' own pages — each pair has an action neither herb has alone.
Energetics dose-weighted
The formula's overall nature, taste balance and channel reach, weighted by each herb's dose. Classical formulas often pair warm and cool herbs on purpose, so a net figure summarises the mix — it doesn't describe every herb in it.
Nature
Net neutral (-0.04)
From 100% of the weighed grams.
Grams by band: cold 11%, cool 30%, neutral 11%, warm 48%.
Pairs warm and cool. 48% of the weighed grams are warm or hot and 41% cool or cold — the net is their average, not the whole story.
Taste
- pungent 37%
- sweet 32%
- bitter 32%
From 100% of the weighed grams.
Channels reached
- Spleen 70%
- Stomach 59%
- Lung 56%
- Gallbladder 41%
- Heart 33%
- Pericardium 30%
Share of the grams entering each channel, from 100% of the weighed grams.
Dose-weighted from each herb's recorded nature, taste and channels (missing values are left out, never counted as neutral). It describes the composition — it is not a recommendation.
Preparation
Traditional double-decoction: decoct all herbs in 1.2L water, reduce to 600mL, remove dregs, reduce to 300mL. Take warm in 3 doses/day.
Dosage
Decoction: 1 dose/day in 2–3 divided doses. Granules: follow package instructions.
Conditions Addressed
Relationships
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Formula Network
Formulas that share herbs with this one — the closer to the centre, the stronger the match. Click a node to explore.
Similar Formulas by composition
Match score combines dosage-weighted composition (cosine, 70%) with shared-herb overlap (Jaccard, 30%).
Traditional formula information is for educational purposes only. Herbal formulas should be prescribed by a qualified practitioner — dosages and combinations are individualized and can interact with medications.
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