Su Zi Jiang Qi Tang (苏子降气汤): Perilla Seed Qi-Descending Decoction for Asthma and Wheezing

What Is Su Zi Jiang Qi Tang?

Su Zi Jiang Qi Tang (苏子降气汤) — the “Perilla Seed Qi-Descending Decoction” — is a masterful formula from the Song dynasty text Tai Ping Hui Min He Ji Ju Fang (太平惠民和剂局方, “Imperial Grace Formulary of the Tai Ping Era,” 1151 CE). It addresses one of the most challenging clinical patterns in TCM: upper excess with lower deficiency (上实下虚) — phlegm and rebellious Qi overwhelming the Lungs above, while the Kidneys below are too weak to anchor the breath.

This formula is the classic prescription for chronic asthma and wheezing where the patient has both acute phlegm obstruction and underlying Kidney weakness. Its genius lies in simultaneously treating the branch (phlegm, rebellious Qi) and the root (Kidney deficiency).

Formula Composition

Herb	Chinese Name	Dosage	Role
Su Zi	苏子	9g	Chief — descends Lung Qi, resolves phlegm, stops wheezing
Ban Xia	半夏	9g	Deputy — transforms phlegm, directs Qi downward
Qian Hu	前胡	6g	Deputy — directs Qi down, resolves phlegm
Hou Po	厚朴	6g	Deputy — moves Qi, resolves fullness
Rou Gui	肉桂	3g	Assistant — warms Kidneys, anchors Qi below
Dang Gui	当归	6g	Assistant — nourishes blood, moistens to prevent drying
Sheng Jiang	生姜	3 slices	Assistant — warms middle, harmonizes
Zhi Gan Cao	炙甘草	3g	Assistant — harmonizes, protects Stomach
Su Ye	苏叶	6g	Assistant — dispels wind, opens the surface

Ingredient Analysis

The Chief Herb — Su Zi (Perilla Seed):

• The seed of the Perilla plant (same plant as Zi Su Ye, the leaf)
• Rich in oils that moisten and lubricate the intestines
• The premier herb for directing Lung Qi downward — the “descending” in the formula’s name
• Resolves phlegm without being harsh
• Also treats constipation, which often accompanies Lung Qi stagnation (Lung-Large Intestine paired organs)

The Phlegm Team — Ban Xia + Qian Hu + Hou Po:

• Ban Xia: The workhorse phlegm-transformer — transforms cold-type phlegm effectively
• Qian Hu: Directs Qi downward and resolves phlegm — supports Su Zi’s descending action
• Hou Po (Magnolia Bark): Moves Qi and relieves chest/abdominal fullness — addresses the feeling of “too much in the chest”

The Root Treatment — Rou Gui + Dang Gui:

• Rou Gui (Cinnamon Bark): Warms the Kidneys and strengthens their ability to “grasp” Lung Qi. In TCM, the Kidneys must “grasp” (纳) the Lung Qi for breathing to be deep and full. When Kidneys are weak, breathing becomes shallow and wheezy.
• Dang Gui: Nourishes blood and moistens — prevents the warm, drying herbs from depleting fluids. Also supports the Liver which plays a role in Qi regulation.

The Harmonizers — Sheng Jiang + Zhi Gan Cao + Su Ye:

• Sheng Jiang: Warms the middle to help transform phlegm; reduces Ban Xia toxicity
• Zhi Gan Cao: Harmonizes all ingredients; protects Stomach
• Su Ye: Opens the surface slightly — helps ventilate the Lungs from the exterior

TCM Pattern: Upper Excess, Lower Deficiency (上实下虚)

Understanding This Complex Pattern

This pattern describes a body with two simultaneous problems:

Upper Excess (上实) — Phlegm and Rebellious Qi in the Lungs:

Symptom	Description
Wheezing	Audible wheezing, especially on exhalation
Copious phlegm	Large amounts of sputum, often thin and white
Cough	Persistent, rattling cough
Chest fullness	Feeling of pressure and fullness in the chest
Shortness of breath	Difficulty taking a full breath

Lower Deficiency (下虚) — Kidney Yang Deficiency:

Symptom	Description
Shallow breathing	Inability to breathe deeply from the abdomen
Worse on exertion	Breathing difficulty increases with activity
Cold lower body	Cold feet, lower back pain
Frequent urination	Kidney Yang fails to transform fluids
Fatigue	Underlying depletion

Tongue: Pale or slightly purple body, white slippery coating Pulse: Deep, weak at the Kidney position; wiry or slippery at the Lung position

Why This Pattern Develops

1. Chronic phlegm accumulation from poor Spleen function (Spleen generates phlegm)
2. Repeated asthma attacks weaken the Lung Qi over time
3. Kidney Yang declines naturally with age or from chronic illness
4. The weakened Kidneys can no longer grasp (纳) the Lung Qi
5. Result: phlegm blocks above while the foundation crumbles below

Clinical Applications

1. Chronic Asthma (慢性哮喘)

The primary application:

• Long-standing asthma with frequent exacerbations
• Wheezing with phlegm sounds
• Better when sitting up, worse when lying down
• Breathing difficulty worsened by cold weather and exertion
• Often in older adults or those with decades of asthma history

2. Chronic Bronchitis with Wheezing (喘息性支气管炎)

• Productive cough with wheezing component
• Copious white or clear phlegm
• Symptoms worse in cold, damp weather
• Patient feels cold from the waist down

3. Emphysema / COPD Support (肺气肿辅助治疗)

• The “upper excess, lower deficiency” pattern matches COPD pathology
• Can be used as complementary treatment alongside Western management
• Helps reduce phlegm, ease breathing, and support Kidney function

4. Cough with Copious Phlegm in Elderly (老年痰咳)

• Elderly patients with chronic productive cough
• Weak constitution with abundant phlegm
• Poor appetite and fatigue
• The formula’s dual action (phlegm resolution + Kidney support) suits this population

Formula Strategy: How It Works

         UPPER BODY (Branch)
    ┌────────────────────────────┐
    │  Phlegm + Rebellious Qi   │  ← Su Zi + Ban Xia + Qian Hu
    │  Blocks the Lungs         │     Descends Qi, resolves phlegm
    └─────────────┬──────────────┘
                  │ Bridge
                  ▼
         LOWER BODY (Root)
    ┌────────────────────────────┐
    │  Kidney Yang Deficiency    │  ← Rou Gui + Dang Gui
    │  Cannot Grasp Lung Qi     │     Warms Kidneys, nourishes Blood
    └────────────────────────────┘

The formula simultaneously:

1. Clears the obstruction — resolves phlegm and descends rebellious Qi in the upper body
2. Strengthens the foundation — warms Kidney Yang so it can properly anchor the breath
3. Prevents collateral damage — Dang Gui and Gan Cao protect against the drying effects of phlegm-resolving herbs

Modern Modifications

Situation	Modification	Purpose
Very copious phlegm	+ Bai Jie Zi, Lai Fu Zi	Stronger phlegm resolution (adds Bai Jie Zi from San Zi Yang Qin Tang)
Severe wheezing	+ Ting Li Zi, Sang Bai Pi	Stronger Qi-descending and wheezing relief
More Kidney cold	+ Bu Gu Zhi, Ge Jie	Stronger Kidney Yang tonification
Yin deficiency signs	Replace Rou Gui with Rou Cong Rong	Gentler Kidney support without excessive warmth
Constipation	Increase Su Zi dose	Su Zi naturally lubricates intestines
Recurrent infections	+ Huang Qi, Fang Feng	Strengthen defensive Qi to prevent colds triggering asthma

Preparation and Usage

As Decoction

• Standard doses as listed above
• Cook in water for 25–30 minutes
• Drink warm, 2 times daily
• For acute exacerbations: 3 times daily until symptoms improve
• Rou Gui should be added toward the end to preserve volatile oils

Long-Term Use

• For chronic conditions, this formula may be taken for weeks to months
• Consider rotating with Kidney-strengthening formulas during remission periods
• Monitor for signs of excess warmth and adjust accordingly

Relationship to Other Asthma Formulas

Formula	Pattern	Key Difference
Su Zi Jiang Qi Tang	Upper excess + lower deficiency	Both branch and root
She Gan Ma Huang Tang	Cold-phlegm with wheezing	Focus on phlegm (no Kidney support)
Xiao Qing Long Tang	External wind-cold + internal fluid retention	Acute onset, more external symptoms
Jin Gui Shen Qi Wan	Kidney Yang deficiency alone	Pure root treatment, no phlegm resolution
Liu Wei Di Huang Wan	Kidney Yin deficiency	For dry-type chronic conditions

Modern Research

Clinical studies on Su Zi Jiang Qi Tang have shown:

• Bronchodilatory — helps relax airway smooth muscle
• Expectorant — promotes mucus clearance from airways
• Anti-inflammatory — reduces airway inflammation
• Antiasthmatic — reduces frequency and severity of asthma attacks
• Anti-allergic — some evidence of reduced allergic response

Research on Su Zi (Perilla seed) specifically has identified rosmarinic acid and luteolin as key anti-inflammatory compounds.

Precautions

Situation	Guidance
Lung heat with yellow thick phlegm	Not ideal — formula is warm in nature; consider Qing Qi Hua Tan Wan instead
Kidney Yin deficiency (no cold signs)	The Rou Gui may be too warming; modify or choose a different formula
Acute asthma attack	Do not rely on herbs alone — seek emergency care if breathing is severely compromised
Pregnancy	Consult practitioner — contains blood-moving and Qi-descending herbs
Hypertension	Rou Gui may raise blood pressure in some patients

Key Takeaways

• Su Zi Jiang Qi Tang is the classic formula for “upper excess, lower deficiency” in asthma
• It simultaneously resolves phlegm above (branch) and warms Kidneys below (root)
• Su Zi (Perilla seed) is the chief herb — premier at descending Lung Qi and stopping wheezing
• The formula treats chronic asthma where phlegm obstruction meets Kidney weakness
• Originally from the Song dynasty Imperial Grace Formulary (1151 CE)
• Modern research confirms bronchodilatory, expectorant, and anti-inflammatory properties
• Not suitable for heat-type asthma or pure Yin deficiency patterns

Disclaimer: This article is for educational purposes only. Consult a licensed TCM practitioner before using Su Zi Jiang Qi Tang or any herbal formula.

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