Bai He Gu Jin Tang — Lily Bulb Decoction to Strengthen Metal

On this page

1. Overview
2. TCM pattern
3. Key herbs
4. Formula actions
5. Conditions treated
6. Cautions

What is Bai He Gu Jin Tang?

Bai He Gu Jin Tang (“Lily Bulb Decoction to Strengthen Metal”) is the classical Chinese formula for chronic dry cough from Lung and Kidney Yin deficiency. The name refers to the strengthening of the “Metal” phase (Lung) by the chief herb Bai He (Lily bulb). The formula nourishes Yin, moistens the Lung, clears Heat and stops cough — addressing the deep depletion pattern often seen in long-standing or post-viral chronic cough, tuberculosis (historically) and bronchiectasis.

Bai He Gu Jin Tang TCM pattern

Prescribed for Lung and Kidney Yin deficiency with Heat from deficiency, characterised by: chronic dry cough, scanty sticky phlegm sometimes streaked with blood, hoarse voice, sore dry throat, low-grade afternoon fever, night sweats, hot palms and soles, malar flush, a red dry tongue with little coat, and a thin rapid pulse.

Key herbs

1. Bai He (lily bulb) — the chief herb; nourishes Lung Yin, clears Lung Heat, stops cough
2. Sheng Di Huang (raw rehmannia) — nourishes Yin, clears Heat, cools Blood
3. Shu Di Huang (prepared rehmannia) — nourishes Kidney Yin and essence
4. Mai Men Dong (Ophiopogon root) — nourishes Lung and Stomach Yin
5. Xuan Shen (scrophularia) — clears deficiency Heat, nourishes Yin
6. Dang Gui — nourishes Blood (paired with Yin tonics to support the Blood-Yin axis)
7. Bai Shao — nourishes Yin and Blood
8. Jie Geng (Platycodon root) — opens the Lung and directs herbs upward
9. Chuan Bei Mu (Fritillaria bulb) — clears Lung Heat, transforms Phlegm, stops cough
10. Gan Cao — harmonises and supplements Qi

Formula actions

1. Nourishes Yin (Lung and Kidney) and moistens the Lung
2. Clears deficiency Heat
3. Transforms Phlegm and stops cough
4. Cools Blood and stops bleeding (haemoptysis)

Conditions treated

1. Chronic dry cough — particularly post-viral, post-COVID, or in the elderly
2. Bronchiectasis with blood-tinged sputum
3. Chronic obstructive pulmonary disease (COPD) with Yin deficiency
4. Chronic laryngitis with hoarseness
5. Pulmonary tuberculosis (adjunctive in historical use)
6. Recurrent chest infections in Yin-deficient patients
7. Smoker’s cough with dryness and irritation

Cautions

Contraindicated in cough from Wind-Cold or Phlegm-Damp patterns. Use cautiously in patients with diarrhoea or Spleen Qi deficiency (the formula is rich and cooling). Always consult a qualified Chinese herbalist registered with the RCHM. Online herbal consultations are available.