Bu Zhong Yi Qi Tang (补中益气汤): The Premier Formula for Spleen Qi Sinking

Introduction to Bu Zhong Yi Qi Tang

Bu Zhong Yi Qi Tang (补中益气汤, Bǔ Zhōng Yì Qì Tāng), translated as “Center-Supplementing Qi-Raising Decoction” or “Tonify Middle and Raise Qi Decoction,” is one of the most celebrated formulas in the entire canon of Traditional Chinese Medicine. Created by the great physician Li Dongyuan (李东垣, 1180–1251) during the Jin Dynasty, this formula represents a masterfully crafted approach to treating a specific and clinically common pattern: Spleen Qi sinking (中气下陷).

Li Dongyuan is regarded as one of the Four Great Masters of Chinese Medicine, alongside Liu Wansu (Liu Hejian), Zhu Danxi (Zhu Danxi), and Zhang Zihe (Zhang Congzheng). His contribution — the recognition of the central role of the Spleen and Stomach in health and disease, and the development of the “Earth school” (脾胃派) of medicine — fundamentally shaped TCM’s understanding of digestive health, fatigue, and deficiency patterns.

Bu Zhong Yi Qi Tang is featured prominently in Li Dongyuan’s seminal work, Pi Wei Lun (《脾胃论》, Treatise on the Spleen and Stomach), written around 1249. In this text, Li argues persuasively that the Spleen and Stomach are the “root of post-natal life” (后天之本) and that most illnesses arise from Spleen-Stomach dysfunction. His therapeutic approach emphasizes warming and tonifying the middle while carefully distinguishing between deficiency and excess.

Core Theory: Spleen Qi Sinking

Before understanding the formula, it is essential to understand the pathological concept it addresses: Spleen Qi sinking.

In TCM physiology, Qi has a natural tendency to ascend — particularly in the case of clear, pure Qi that rises to feed the Heart and Lungs. The Spleen’s Qi normally “holds” the organs in place and ascends to the Lungs as part of the ascending-descending dynamic of the Six Yin Organs. When Spleen Qi becomes deficient, it loses this lifting function and “sinks” downward.

This sinking manifests in several characteristic ways:

Symptom Pattern	Clinical Manifestation
Organ prolapse	Uterine prolapse, rectal prolapse, gastroptosis (stomach falling), bladder prolapse
Chronic diarrhea	Persistent loose stools, especially worse in the morning, from Spleen Qi failing to transform fluids
Fatigue and heaviness	Severe fatigue, especially of the lower body, heavy limbs, difficulty keeping eyes open
Shortness of breath	Breathlessness that worsens with exertion, weak voice
Spontaneous sweating	Sweating without obvious cause, often with cold sweats
Aversion to cold	Preference for warmth, cold limbs

Li Dongyuan’s genius was recognizing that simply tonifying Spleen Qi was not enough — one also needed to “raise the sunken” (升提) by adding herbs with an ascending action. This dual approach — simultaneously tonifying and raising — is the hallmark of Bu Zhong Yi Qi Tang.

Formula Composition

Bu Zhong Yi Qi Tang is composed of eight herbs, built upon the foundation of Si Jun Zi Tang (Four Gentlemen Decoction):

Herb (Chinese)	Herb (English)	Pinyin	Role	Dose Range
黄芪	Astragalus root	Huáng Qí	君药 (Chief)	3–9 g
人参	Ginseng	Rén Shēn	臣药 (Deputy)	3–6 g
炙甘草	Honey-fried Licorice root	Zhì Gān Cǎo	臣药 (Deputy)	3–6 g
白术	White Atractylodes	Bái Zhú	佐药 (Assistant)	3–6 g
当归	Angelica sinensis root	Dāng Guī	佐药 (Assistant)	3–6 g
陈皮	Tangerine peel	Chén Pí	佐药 (Assistant)	3–6 g
升麻	Cimicifuga (Bugbane) rhizome	Shēng Má	使药 (Envoy)	1.5–3 g
柴胡	Bupleurum root	Chái Hú	使药 (Envoy)	1.5–3 g

Formula Architecture

The formula’s design reflects sophisticated TCM pharmacological reasoning:

Foundation — Si Jun Zi Tang (Four Gentlemen):

• Huang Qi (Astragalus): The chief herb — the most powerful Spleen-Qi tonic, also raises Yang and stabilizes the exterior
• Ren Shen (Ginseng): A powerful Qi tonic that strongly nourishes the original Qi (Yuan Qi)
• Bai Zhu (White Atractylodes): Strengthens the Spleen’s transformation and transportation functions
• Zhi Gan Cao (Honey-fried Licorice): Harmonizes the formula, nourishes the Spleen, and moderates the strong properties of Huang Qi and Ren Shen

Blood Nourishment:

• Dang Gui (Angelica): Nourishes Blood to prevent the formula from becoming too drying. Li Dongyuan carefully reasoned that Yin and Blood must be nourished alongside Qi tonification to avoid “injuring Yin.”

Qi Regulation — Preventing Stagnation:

• Chen Pi (Tangerine Peel): Promotes Qi movement and prevents the cloying nature of tonic herbs from causing stagnation in the middle burner. It also guides the formula’s actions to the Spleen and Stomach.

The Key Innovation — Raising Sunken Qi:

• Sheng Ma (Cimicifuga): The herb with the strongest ascending action in the materia medica. It specifically “raises Yang and lifts the sunk” — the primary herb for treating prolapse and Spleen Qi sinking.
• Chai Hu (Bupleurum): Another ascending herb that raises clear Yang and relieves Liver Qi stagnation. It harmonizes the middle and assists Sheng Ma in raising.

The combination of Sheng Ma and Chai Hu is the formula’s defining feature — these two ascending herbs give Bu Zhong Yi Qi Tang its unique ability to address sinking and prolapse, differentiating it from Si Jun Zi Tang which merely tonifies Qi.

Indications and Clinical Applications

Bu Zhong Yi Qi Tang is indicated for Spleen Qi deficiency with Spleen Qi sinking. Key diagnostic indicators include:

Core Indications

1. Fatigue and Weakness

   • Severe, persistent tiredness — not relieved by rest
   • Worsened by physical exertion
   • Difficulty keeping eyes open (“can’t keep eyes up”)
   • Heaviness in the limbs
   • Often associated with a pale tongue with a thin white coating

2. Prolapse Patterns

   • Uterine prolapse (子宫脱垂)
   • Rectal prolapse (脱肛)
   • Gastroptosis (胃下垂)
   • Hemorrhoids (especially prolapsing hemorrhoids)
   • The hallmark symptom — symptoms improve after taking the formula

3. Chronic Diarrhea

   • Loose stools or watery diarrhea
   • Often worse in the morning (五更泄)
   • Sensation of incomplete evacuation
   • May include undigested food in stools

4. Shortness of Breath

   • Breathlessness on exertion
   • Weak, low voice
   • Spontaneous sweating
   • These symptoms indicate Lung Qi deficiency alongside Spleen Qi deficiency

5. Chronic Illness Recovery

   • Used widely as a recovery tonic after prolonged illness, surgery, or childbirth
   • Supports rebuilding of Spleen and Lung Qi
   • Particularly useful for post-viral fatigue syndromes

Extended Applications in Modern Practice

Condition	TCM Pattern	Application
Long COVID / post-viral fatigue	Spleen Qi deficiency with sinking	Primary formula for persistent fatigue after illness
Functional gastrointestinal disorders	Spleen Qi sinking	Chronic gastritis, gastroparesis, chronic diarrhea
Gynecological prolapse	Spleen and Kidney Qi sinking	Uterine prolapse, bladder prolapse
Hemorrhoids	Spleen Qi sinking	Prolapsing, bleeding hemorrhoids
Chronic otitis media	Spleen Qi deficiency	Recurrent ear infections, Eustachian tube dysfunction
Myasthenia gravis	Spleen Qi deficiency	Fatigue-relieving support alongside other treatment
Orthostatic hypotension	Spleen Qi deficiency	Dizziness upon standing, low blood pressure
Prolonged fever	Deficiency fever (气虚发热)	Low-grade fever from Qi deficiency

Modifications for Specific Patterns

The classical text Pi Wei Lun provides numerous modifications demonstrating the formula’s flexibility:

Modification	Added Herbs	Indication
+ Sheng Jiang (9 slices)	Fresh Ginger	Nausea and vomiting
+ Sha Ren	Amomum	Severe diarrhea with Dampness
+ Bai Bian Dou	Hyacinth Bean	Diarrhea with weak digestion
+ E Jiao	Donkey-hide gelatin	Blood deficiency with excessive bleeding
+ Huang Bo	Phellodendron bark	Spleen deficiency with Damp-Heat
+ Wu Wei Zi	Schisandra	Severe spontaneous sweating
+ Shan Yao	Chinese Yam	Chronic diarrhea with weak back

The “Deficiency Heat” Theory and Li Dongyuan’s Insight

One of Li Dongyuan’s most important contributions was his recognition that Qi deficiency can itself generate heat. This pattern, known as deficiency heat (虚热) or “deficiency fire” (虚火), arises when weakened Spleen Qi fails to properly transform food and fluids, leading to the accumulation of dampness that transforms into heat over time.

This insight was revolutionary because:

• Deficiency heat presents like excess heat (fever, irritability, thirst) — but it should not be treated with heat-clearing herbs
• Treating deficiency heat with cold herbs would further damage the Spleen and worsen the condition
• The correct approach is to tonify the Spleen to remove the root cause — the heat will resolve on its own

Bu Zhong Yi Qi Tang, with its combination of warming tonics and ascending herbs, addresses this pattern perfectly by treating the root (Spleen Qi deficiency) rather than the branch (heat).

Bu Zhong Yi Qi Tang vs. Other Related Formulas

Formula	Key Difference	Primary Use
Bu Zhong Yi Qi Tang	Adds ascending herbs (Sheng Ma, Chai Hu) for sinking	Spleen Qi sinking with prolapse
Si Jun Zi Tang	Basic Qi tonification without raising action	Simple Spleen Qi deficiency
Sheng Mai San	Tonifies Lung Qi and generates fluids	Lung Qi and Yin deficiency
Xiang Sha Liu Jun Zi Tang	Adds herbs for Damp-Phlegm, moves Qi	Spleen Qi deficiency with Phlegm and Qi stagnation
Ju Pi Zhu Ru Tang	Focuses on nausea, vomiting, epigastric discomfort	Spleen-Stomach Qi deficiency with rebellious Qi
Yi Qi Cong Ming Tang	Adds herbs for hearing and vision	Qi deficiency with hearing/vision impairment

Dosage and Preparation

Standard Decoction Method:

1. Rinse herbs briefly
2. Simmer Huang Qi, Ren Shen, Bai Zhu, Sheng Ma, and Chai Hu in water for 20–30 minutes
3. Add Dang Gui, Zhi Gan Cao, and Chen Pi in the last 10 minutes
4. Typical dose: 200–300 ml of decoction, taken in two divided doses
5. Often taken on an empty stomach (before meals) for maximum absorption

Modern Granule: 3–6 g of freeze-dried granule, twice daily, dissolved in warm water.

Powder Form: 6–9 g, taken with warm water, twice daily.

Li Dongyuan originally recommended taking the formula in the morning on an empty stomach — a practice still followed by many TCM practitioners today, as it aligns with the Spleen’s peak hours (9–11 AM) and avoids interference from food digestion.

Cautions and Contraindications

• False Qi deficiency: Should not be used when fatigue is due to Yin deficiency or Blood deficiency alone — adding warming tonics would worsen these patterns
• Damp-Heat excess: Not appropriate when Damp-Heat signs predominate (yellow tongue coating, bitter taste, urinary dysfunction)
• Food stagnation: Not appropriate when there is significant Qi stagnation or Food stagnation
• High blood pressure: The ginseng component may interact with certain antihypertensive medications
• Fever from external pathogens: Not appropriate for acute febrile conditions
• Pregnancy: Should only be used during pregnancy under professional supervision

Conclusion

Bu Zhong Yi Qi Tang stands as a testament to the depth of clinical insight in classical TCM. Li Dongyuan’s observation that Spleen Qi deficiency leads to sinking — and that sinking must be addressed with ascending herbs alongside tonification — represents one of the most elegant therapeutic strategies in Chinese medicine.

This formula’s enduring relevance is proven by its widespread use in modern TCM practice, from post-operative recovery to long COVID fatigue management. Its careful balance of eight herbs — tonifying Spleen Qi, raising sunken Yang, nourishing Blood, and preventing stagnation — remains a model of classical formula construction.

For practitioners, Bu Zhong Yi Qi Tang is not merely a formula to be prescribed — it is a window into Li Dongyuan’s profound understanding of the Spleen’s role in health, and an invitation to think deeply about the relationship between organ function, Qi dynamics, and the clinical patterns that arise from their disruption.

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References

1. Li, D. (1249). Pi Wei Lun (Treatise on the Spleen and Stomach). Trans. by Flaws, B. (1995). Boulder: Blue Poppy Press.
2. Scheid, V., Bensky, D., Ellis, A., & Barolet, R. (2009). Chinese Herbal Medicine: Formulas & Strategies (2nd ed.). Seattle: Eastland Press.
3. Chen, J.K. & Chen, T.T. (2004). Chinese Herbal Medicine: Materia Medica. Seattle: Eastland Press.