Xiang Su San (香苏散): Cyperus and Perilla Powder — Calming the Stomach While Releasing the Exterior
Learn about Xiang Su San, the elegant Song Dynasty formula that simultaneously releases exterior wind-cold and regulates Qi — ideal for colds accompanied by stomach discomfort, emotional stress, and chest fullness.
What Is Xiang Su San?
Xiang Su San (香苏散), the “Cyperus and Perilla Powder,” is a classical formula from the Song Dynasty, recorded in the Tai Ping Hui Min He Ji Ju Fang (Imperial Grace Formulary, 1110 AD). It is an elegant, compact formula that simultaneously releases exterior wind-cold AND regulates Qi in the middle Jiao — making it ideal for colds that also cause digestive discomfort and emotional tension.
The name comes from its two chief herbs: Xiang Fu (Cyperus) and Su Ye (Perilla leaf) — together they move Qi and release the exterior in a harmonious, gentle way.
Formula Composition
| Herb | Pinyin | Dosage | Role |
|---|---|---|---|
| Purple perilla leaf | Su Ye | 9g | Chief — Releases exterior wind-cold, moves Qi, harmonizes middle |
| Cyperus | Xiang Fu | 9g | Deputy — Regulates Liver Qi, relieves stagnation |
| Tangerine peel | Chen Pi | 6g | Assistant — Regulates Spleen Qi, resolves dampness |
| Licorice | Gan Cao | 3g | Envoy — Harmonizes, supports Spleen |
Formula Analysis
Only four herbs, but they create a complete treatment:
Exterior release:
- Su Ye (Perilla) — warms and releases the exterior, moves Qi, harmonizes the middle Jiao
- The primary herb does double duty — treats the cold and the digestion
Qi regulation:
- Xiang Fu (Cyperus) — the premier Qi-regulating herb for Liver stagnation
- Chen Pi (Tangerine peel) — regulates Spleen Qi, resolves damp, supports digestion
Harmonization:
- Gan Cao — brings all herbs together, supports Spleen
The genius: Su Ye is both an exterior-releasing AND Qi-moving herb, bridging the two treatment goals in a single ingredient.
Primary Indications
Core Pattern: Wind-Cold Exterior + Middle Jiao Qi Stagnation
Key symptoms:
- Chills, mild fever — wind-cold exterior pattern
- Headache — from wind-cold
- No sweating — exterior not released
- Chest and epigastric fullness — Qi stagnation in middle Jiao
- Loss of appetite — Spleen/Stomach Qi not moving
- Stomach discomfort — Qi stagnation
- Possible emotional stress — Liver Qi stagnation contributing
Tongue and Pulse
| Sign | Typical Finding |
|---|---|
| Tongue | Normal or slightly pale, thin white coat |
| Pulse | Floating (exterior) and wiry (Qi stagnation) |
Clinical Applications
1. Colds with Digestive Symptoms
- Common cold with chills, headache, and stomach fullness
- The cold affects both the respiratory and digestive systems
- Patient feels “blocked” — both in the head and the stomach
- The combined exterior-interior approach is more effective than treating either alone
2. Stress-Related Cold
- Colds that develop during or after periods of emotional stress
- Liver Qi stagnation (from stress) makes the body more susceptible to external pathogens
- The Qi-regulating herbs address both the stress and the cold vulnerability
3. Mild Gastrointestinal Cold
- Body aches and chills with nausea and poor appetite
- “Stomach flu” with cold-type pattern
- Less severe than conditions requiring Huo Xiang Zheng Qi San
4. Seasonal Transitions
- Colds that occur during weather changes
- When patients are under stress during seasonal transitions
- The gentle nature makes it suitable for sensitive patients
Comparison with Related Formulas
vs. Gui Zhi Tang
| Feature | Gui Zhi Tang | Xiang Su San |
|---|---|---|
| Exterior pattern | Wind-cold with deficiency | Wind-cold with Qi stagnation |
| Key differentiator | Sweating + stiff neck | Chest fullness + stomach discomfort |
| Digestive focus | Minimal | Strong Qi-regulating |
vs. Huo Xiang Zheng Qi San
| Feature | Huo Xiang Zheng Qi San | Xiang Su San |
|---|---|---|
| Primary focus | Damp-cold in middle Jiao | Qi stagnation + wind-cold |
| Digestive severity | More severe (nausea, vomiting, diarrhea) | Milder (fullness, poor appetite) |
| Herb count | Large (10+ herbs) | Small (4 herbs) |
| Best for | Significant damp-cold | Mild cold + mild digestive issues |
vs. Xiao Qing Long Tang
- Xiao Qing Long Tang: Wind-cold with phlegm-fluid (cough with watery sputum)
- Xiang Su San: Wind-cold with Qi stagnation (chest/stomach fullness)
Dosage and Administration
Decoction
- Soak herbs 20 minutes
- Simmer 15-20 minutes (Su Ye is aromatic — don’t overcook)
- Add Su Ye in the last 5 minutes to preserve volatile oils
- Drink warm, 2-3 times daily
- Best taken shortly after onset of symptoms
Powder Form (Traditional)
- Grind herbs into fine powder
- 6-9g per dose, taken with warm water or warm tea
- The traditional form preserves the aromatic properties
Patent Forms
- Available as pills and powders from TCM manufacturers
- Follow manufacturer’s recommended dosage
Modern Clinical Use
Xiang Su San is commonly used for:
- Early-stage common cold with concurrent stomach upset
- Seasonal allergy episodes with chest fullness
- Stress-related colds in overworked patients
- Mild gastrointestinal upset during weather changes
It is also used as a base formula that practitioners modify by adding herbs for specific symptoms:
-
- Jie Geng (Platycodon) for sore throat
-
- Ban Xia (Pinellia) for nausea
-
- Fang Feng (Saposhnikovia) for stronger exterior release
-
- Bai Zhu (Atractylodes) for Spleen weakness
Cautions
| Situation | Guidance |
|---|---|
| Wind-heat pattern | Not suitable — warming herbs aggravate heat |
| High fever | Too mild for severe heat conditions |
| Severe vomiting/diarrhea | Use Huo Xiang Zheng Qi San instead |
| Yin deficiency | Warming herbs may aggravate |
Key Takeaways
- Xiang Su San is a compact 4-herb formula that treats wind-cold + Qi stagnation simultaneously
- Best for colds with chest/stomach fullness, poor appetite, and emotional stress
- Su Ye (Perilla) is the key herb — bridges exterior release and Qi regulation
- Gentle and well-tolerated — suitable for sensitive patients
- Too mild for severe conditions — use stronger formulas when needed
Disclaimer: This article is for educational purposes only. Consult a licensed TCM practitioner before using this formula.
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FAQ
What is Xiang Su San used for?
Xiang Su San is used for wind-cold type common cold that is accompanied by Qi stagnation symptoms — specifically chest and epigastric fullness, stomach discomfort, and a feeling of distension. It is ideal when a patient has cold symptoms (chills, headache, no sweating) but also has loss of appetite, stomach fullness, and possibly emotional stress. The formula simultaneously releases the exterior (treats the cold) and regulates Qi (treats the digestive discomfort), making it a practical choice for colds that affect both the respiratory and digestive systems.
Can Xiang Su San be used for stomach flu?
Xiang Su San can be helpful for mild stomach flu when the pattern matches: chills, body aches, no sweating (wind-cold) combined with nausea, stomach fullness, and loss of appetite (Qi stagnation in the middle Jiao). However, for more severe gastrointestinal symptoms — such as vomiting, diarrhea, or significant damp-heat — other formulas like Huo Xiang Zheng Qi San may be more appropriate. Xiang Su San is best for the mild-to-moderate presentation where cold and digestive symptoms are roughly equal.
Disclaimer
This content is for educational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional before using any herbal formula.