Yi Zi Tang
Star乙字汤 (Yi Word Decoction)
Source: Asada's Prescriptions — Sohaku Asada (1820)
Last updated October 1, 2026
Description
Yi Zi Tang (Yi Word Decoction), from the Asada's Prescriptions by Sohaku Asada.
Actions: Clears heat and promotes bowel movement; Cools the blood and eliminates toxins; Raises yang qi.
Presentation: Dampness, heat and toxins accumulated in the lower jiao: hemorrhoids, constipation, severe local pain, slight bleeding; also women with menstrual or vaginal bleeding, abdominal pain, and dark clotted blood.
Source: Chen JK, Chen TT. Chinese Herbal Formulas and Applications: Pharmacological Effects & Clinical Research. Art of Medicine Press, 2009, p. 164.
Composition
| Herb | Amount | % | Role | Function |
|---|---|---|---|---|
|
Chai Hu
as printed: Chai Hu (Radix Bupleuri) 5g
|
5g | 26.32% | With Sheng Ma, lifts qi and restores the rectum to its normal position | |
|
Sheng Ma
as printed: Sheng Ma (Rhizoma Cimicifugae) 1g
|
1g | 5.26% | With Chai Hu, lifts qi | |
|
Dang Gui
as printed: Dang Gui (Radix Angelicae Sinensis) 6g
|
6g | 31.58% | With Gan Cao, nourishes and replenishes lost blood and relieves pain | |
|
Gan Cao
as printed: Gan Cao (Radix et Rhizoma Glycyrrhizae) 3g
|
3g | 15.79% | With Dang Gui, nourishes blood and relieves pain | |
|
Huang Qin
as printed: Huang Qin (Radix Scutellariae) 3g
|
3g | 15.79% | With Da Huang, clears damp-heat and toxins from the Large Intestine | |
|
Da Huang
as printed: Da Huang (Radix et Rhizoma Rhei) 1g
|
1g | 5.26% | With Huang Qin, clears damp-heat and toxins and promotes peristalsis |
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 slightly cool (-0.42)
From 100% of the weighed grams.
Grams by band: cold 21%, cool 32%, neutral 16%, warm 32%.
Pairs warm and cool. 32% of the weighed grams are warm or hot and 53% cool or cold — the net is their average, not the whole story.
Small but decisive: Da Huang 1g (cold, 5% of the grams). Dose weighting nearly cancels a herb this small, but it may be what the formula is for.
Taste
- pungent 32%
- sweet 34%
- bitter 34%
From 100% of the weighed grams.
Channels reached
- Spleen 74%
- Heart 63%
- Liver 63%
- Stomach 42%
- Gallbladder 42%
- Lung 37%
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
Source: cook in 1 bowl of water reduced by half; take warm in 2-3 equal doses daily. Today it may be decocted at roughly two to three times the listed doses.
Relationships
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Formula family
Each entry reads as the larger formula written out: “+” adds its other catalogue cores, then the herbs none of them hold. A catalogue formula counts as a core only when at least 80% of its herbs are present, no more than 1 is absent, and the absent herb is not its chief.
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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