Er Chen Tang (二陈汤) — Two-Cured Decoction

Er Chen Tang is a classical Chinese herbal formula used primarily for respiratory conditions with phlegm-damp cough^[10] — chronic bronchitis, copd and recurrent chest infections with copious phlegm. It is prescribed for Phlegm-Damp obstructing the Middle Jiao, characterised by: cough with copious white or grey phlegm, nausea^[12], a sensation of fullness in the chest and epigastrium, dizziness^[22], palpitations, a swollen tongue with thick greasy white coating, and a slippery (Hua) pulse.

On this page

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

What is Er Chen Tang?

Er Chen Tang — Two-Cured Decoction — is the foundational formula for resolving Phlegm-Damp in Chinese herbal medicine. Named after its two principal aged and processed herbs (Ban Xia and Chen Pi), it dates to the Song Dynasty and serves as the base from which dozens of derivative Phlegm-resolving formulas are built. Phlegm-Damp is an extremely common pathological product generated by weak Spleen function, poor diet and sedentary lifestyle, making Er Chen Tang one of the most frequently modified base formulas in clinical use.

Er Chen Tang TCM pattern

Prescribed for Phlegm-Damp obstructing the Middle Jiao, characterised by: cough with copious white or grey phlegm, nausea, a sensation of fullness in the chest and epigastrium, dizziness, palpitations, a swollen tongue with thick greasy white coating, and a slippery (Hua) pulse.

Key herbs

1. Ban Xia (Pinellia ternata rhizome, processed, 5-15g) — the principal herb; dries Dampness, transforms Phlegm, descends Rebellious Qi and stops nausea
2. Chen Pi (aged Citrus reticulata peel, 3-15g) — regulates Qi, dries Dampness and transforms Phlegm
3. Fu Ling (Poria cocos, 5-15g) — tonifies Spleen Qi and leaches out Dampness, addressing the root cause of Phlegm production
4. Zhi Gan Cao (honey-fried Glycyrrhiza root, 1-9g) — tonifies Spleen Qi and harmonises the formula
5. Sheng Jiang (fresh Zingiber officinale rhizome, 3-12g) — warms the Middle and assists Ban Xia in drying Dampness
6. Wu Mei (Prunus mume fruit) — astringes and prevents the drying herbs from damaging Yin

Formula actions

1. Dries Dampness and transforms Phlegm
2. Regulates Qi
3. Harmonises the Middle Jiao

Conditions treated

1. Respiratory conditions with Phlegm-Damp cough — chronic bronchitis, COPD and recurrent chest infections with copious phlegm
2. Nausea and vomiting from Phlegm-Damp, including morning sickness in pregnancy (in modified form)
3. IBS[5] and digestive disorders with Phlegm-Damp obstructing the Middle Jiao
4. Dizziness and vertigo from Phlegm-Damp rising to disturb the head
5. Fatty liver disease — as part of complex formulas for Phlegm-Damp accumulation

Cautions

Always consult a qualified Chinese herbalist registered with the Register of Chinese Herbal Medicine (RCHM). Online herbal consultations are available. See the prices page for costs.

Prefer to be treated from home? Chinese herbal medicine online consultations are available throughout the UK and worldwide. After a full video consultation, Dr (TCM) Attilio D'Alberto formulates a bespoke herbal prescription and posts your Chinese herbs directly to your door.

Frequently asked questions about Er Chen Tang

What is Er Chen Tang used for?

Er Chen Tang is used for respiratory conditions with phlegm-damp cough — chronic bronchitis, copd and recurrent chest infections with copious phlegm, nausea and vomiting from phlegm-damp, including morning sickness in pregnancy (in modified form), ibs and digestive disorders with phlegm-damp obstructing the middle jiao, dizziness and vertigo from phlegm-damp rising to disturb the head, fatty liver disease — as part of complex formulas for phlegm-damp accumulation. The formula targets the underlying TCM pattern producing these symptoms rather than the symptom in isolation, which is why pattern diagnosis by a qualified herbalist is essential.

How does Er Chen Tang work?

The herbs in Er Chen Tang work together: Ban Xia (Pinellia ternata rhizome, processed, 5 15g) — the principal herb; dries dampness, transforms phlegm, descends rebellious qi and stops nausea; Chen Pi (aged Citrus reticulata peel, 3 15g) — regulates qi, dries dampness and transforms phlegm; Fu Ling (Poria cocos, 5 15g) — tonifies spleen qi and leaches out dampness, addressing the root cause of phlegm production; Zhi Gan Cao (honey fried glycyrrhiza root, 1-9g) — tonifies spleen qi and harmonises the formula. The synergy of these actions addresses the underlying TCM pattern.

How long does Er Chen Tang take to work?

For most patients, an improvement is typically noticed within 2–4 weeks of daily granule treatment. Full benefit usually requires 6–12 weeks, depending on how long-standing the underlying pattern is. Er Chen Tang is typically prescribed as part of an individualised treatment plan that may include other herbs or adjustments over time.

Is Er Chen Tang safe in pregnancy?

Use of Er Chen Tang in pregnancy should only be considered under the supervision of a qualified RCHM herbalist with pregnancy training, and only when the TCM pattern specifically calls for it.

Who should not take Er Chen Tang?

Always consult a qualified Chinese herbalist registered with the Register of Chinese Herbal Medicine (RCHM). Online herbal consultations are available. See the prices page for costs. Prefer to be treated from home? Chinese herbal medicine online consultations are available throughout the UK and worldwide. After a full video consultation, Dr (TCM) Attilio D'Alberto formulates a bespoke herbal prescription and posts your Chinese herbs directly to your door. Er Chen Tang must be prescribed only after full pattern diagnosis by a qualified RCHM herbalist; self-prescription is not appropriate.

References

[5] Liu Q, Shi Z, Zhang T, Jiang T, Luo X, Su X, Yang Y, Wei W. Efficacy and Safety of Chinese Herbal Medicine Xiao Yao San in Functional Gastrointestinal Disorders: A meta-Analysis and Trial Sequential Analysis of Randomized Controlled Trials. Front Pharmacol. 2022 Jan 19;12:821802. https://doi.org/10.3389/fphar.2021.821802. PMID: 35126152.

[10] Lee B, Kwon CY, Suh HW, Kim YJ, Kim KI, Lee BJ, Lee JH. Herbal medicine for the treatment of chronic cough: a systematic review and meta-analysis. Front Pharmacol. 2023 Oct 17;14:1230604. https://doi.org/10.3389/fphar.2023.1230604. PMID: 37920213.

[12] Zhai X, He Q, Chen M, Yu L, Tong C, Chen Y, et al. Pinellia ternata-containing traditional Chinese medicine combined with 5-HT3RAs for chemotherapy-induced nausea and vomiting: A PRISMA-compliant systematic review and meta-analysis of 22 RCTs. Phytomedicine. 2023 Jul;115:154823. https://doi.org/10.1016/j.phymed.2023.154823. PMID: 37099981.

[22] Guo Z, Su Z, Wang Z, Luo X, Lai R. The effect of Chinese herbal medicine Banxia Baizhu Tianma Decoction for the treatment of vertebrobasilar insufficiency vertigo: A systematic review and meta-analysis of randomized controlled trials. Complement Ther Med. 2017 Apr;31:27-38. https://doi.org/10.1016/j.ctim.2017.01.004. PMID: 28434468.