Sang Xing Tang: A Classic TCM Formula for Lung Health and Dryness Relief
Health Lab- Feb 21
- 4 min read
Updated: May 3
Sang Xing Tang, introduced in Treatise on Febrile Diseases by Qing Dynasty physician Wu Jutong, is a revered traditional Chinese medicine (TCM) formula designed to address warm-dryness syndromes affecting the lungs.
Noted in the text for treating “dryness damaging the Qi of the hand Taiyin (lung meridian)” with symptoms like dry cough and thirst, this prescription clears heat, moistens the lungs, and resolves phlegm. Its gentle, effective approach makes it a go-to remedy for respiratory issues caused by autumnal dryness or heat.
Formula Composition
Sang Xing Tang comprises seven herbs, organized according to the TCM principle of “monarch, minister, assistant, and envoy”:
Monarch Herb:
Sang Ye (Mulberry Leaf): Light and cooling, it disperses wind-heat, clears lung dryness, and moistens the lungs to relieve cough.
Minister Herbs:
Xing Ren (Apricot Kernel): Lowers lung Qi, moistens dryness, and eases cough and phlegm.
Sha Shen (Adenophora Root): Sweet and cold, it nourishes lung Yin, clears heat, and promotes fluid production.
Zhe Bei Mu (Fritillaria Bulb): Clears heat, resolves phlegm, and soothes cough.
Dan Dou Chi (Prepared Soybean): Gently disperses surface pathogens, aiding in pathogen expulsion.
Assistant Herbs:
Da Zao (Jujube): Clears lung heat and supports spleen function.
Li Pi (Pear Peel): Moistens the lungs, clears heat, and promotes fluid to relieve cough.
This harmonious blend clears heat, nourishes lung Yin, and restores respiratory balance.
Pathogenesis: Understanding the Condition
Sang Xing Tang targets “exogenous warm-dryness syndrome,” common in dry autumn weather when dryness invades the lungs, depleting fluids and impairing lung function. This leads to:
Mild fever and thirst.
Dry throat, nose, and cough with little or sticky phlegm.
Red tongue and rapid pulse.
These symptoms arise from dryness consuming lung fluids, disrupting the lungs’ ability to moisten and regulate Qi. Sang Xing Tang uses cooling, moistening herbs to dispel wind-heat, restore fluids, and support lung health, making it ideal for early-stage dryness syndromes.
Therapeutic Effects of Sang Xing Tang
Sang Xing Tang offers multiple benefits:
Clearing Heat and Dryness: Mulberry leaf and Fritillaria remove heat and wind pathogens, restoring lung clarity.
Moistening the Lungs: Adenophora, pear peel, and jujube nourish Yin and fluids, soothing dryness and thirst.
Resolving Phlegm and Cough: Apricot kernel and Fritillaria clear sticky phlegm, easing dry cough.
Dispersing Pathogens: Prepared soybean gently expels external evils, aiding recovery.
By balancing cooling and moistening actions, the formula relieves respiratory discomfort and supports lung function.
Modern Applications
In modern medicine, Sang Xing Tang is used for respiratory conditions caused by warm-dryness or heat, including:
Upper respiratory infections.
Acute or chronic bronchitis.
Bronchiectasis with hemoptysis.
Whooping cough.
Research highlights its anti-inflammatory, antibacterial, and antiviral properties, which support its clinical use in alleviating cough, phlegm, and inflammation. Its gentle nature makes it suitable for both acute and chronic respiratory issues aligned with dryness syndromes.
Precautions for Use
When using Sang Xing Tang, consider the following:
Syndrome Differentiation: Ensure symptoms match warm-dryness lung injury (e.g., dry cough, rapid pulse). Misuse in non-dryness cases may reduce efficacy.
Contraindications: Avoid in patients with excessive cold-dampness or weak spleen-stomach function, as the formula’s cooling nature may worsen these conditions.
Chinese Name | 桑杏湯 |
Phonetic | Sang Xing Tang |
English Name | Mulberry Leaf and Apricot Kernel Decoction |
Classification | Dryness-moistening formulas |
Source | 《Systematic Differentiation of Warm Diseases》Wen Bing Tiao Bian《溫病條辨》 |
Combination | Mori Folium (Sang Ye) 1 qian (3g), Armeniacae Semen Amarum (Xing Ren) 1.5 qian (4.5g), Glehniae Radix (Bei Sha Shen) 2 qian (6g), Fritillariae Thunbergii Bulbus (Zhe Bei Mu) 1 qian (3g), Sojae Semen Praeparatum (Dan Dou Chi) 1 qian (3g), Gardeniae Pericarpium (Zhi Zi Pi) 1 qian (3g), Gardeniae Pericarpium (Li Pi) 1 qian (3g) |
Method | Decoct the ingredients with 2 cups of water until it is reduced to 1 cup. Take the strained decoction once a day. If the condition is severe continue to take 1 cup each day. (Modern use: prepare the ingredients as a decoction). |
Action | Clears and diffuses warm-dryness, moistens the lung and dissolves phlegm. |
Indication | Sang Xing Tang is indicated for the pattern of externally-contracted warm-dryness. The symptoms are mild fever, thirst, dry throat and nasal cavities, dry cough without sputum, or with scanty, and sticky sputum. The tongue body is red with a thin, white and dry coating. The pulse is floating and rapid and is large on the right side. |
Pathogenesis | Sang Xing Tang is designed to treat mild patterns of externally-contracted warm-dryness injuring the lung fluids. Since warm-dryness invades the lung-wei in autumn, the resulting condition is mild and occurs at the exterior level to induce a mild fever. Dryness also depletes the lung fluids causing failure of the lung qi to purify leading to symptoms such as thirst, dry throat and nasal cavities, dry cough without sputum, or with scanty, and sticky sputum. This pattern resembles exterior wind-heat, yet this pattern is caused by warm-dryness. The lung fluids have been depleted and therefore the therapeutic principle is to clear and diffuse dryness-heat at the exterior, moisten the lung and dissolve phlegm in the interior. |
Application | 1. Essential pattern differentiation Sang Xing Tang is a formula commonly used to treat mild patterns of warm-dryness that have damaged the lung. This clinical pattern is marked by mild fever, dry cough without sputum, or with scantyand sticky sputum, rapid and large pulse on the right. 2. Modern applications This formula may be used in the following biomedically defined disorders when the patient shows signs of externally-contracted warm-dryness invading lung-wei: upper respiratory tract infection, acute and chronic bronchitis, haemoptysis and pertussis. 3. Cautions and contraindications The medicinals in this formula should be used in small dosage and should only be cooked for a short period of time because the pathogens are not severe and are located in the superficial layer. It was explained in a postscript from the formula’s source text: “Light medicinals should not be used in large dosage or decocted for a long time because if they are, light medicinals cannot act at the qi level but will act on the other levels” . |
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