San Zi Yang Qin Tang (三子养亲汤) — Three-Seed Decoction to Nourish One’s Parents

San Zi Yang Qin Tang is the classical Chinese herbal formula for chronic productive cough^[10] with copious Phlegm in older adults — chronic bronchitis, COPD, persistent post-viral cough — where stronger Phlegm-resolving herbs would damage already-depleted Qi. The Ming-dynasty formula combines just three seeds — Bai Jie Zi (white mustard seed), Su Zi (perilla seed) and Lai Fu Zi (radish seed) — in a mild, well-tolerated decoction suited to long-term use in elderly patients. Its name reflects filial piety: a son’s gentle three-seed remedy for an elderly parent’s chronic cough.

On this page

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

Overview

San Zi Yang Qin Tang — the “Three-Seed Decoction to Nourish One’s Parents” (the name reflects filial piety: a son’s gentle three-seed remedy for an elderly parent’s chronic cough) — is a Ming-dynasty formula. It addresses chronic productive cough with copious Phlegm in older adults, where stronger Phlegm-resolving herbs would damage the depleted Qi.

Just three seeds: Bai Jie Zi (white mustard seed), Su Zi (perilla seed) and Lai Fu Zi (radish seed). Mild but effective, suited to chronic use in older patients.

I prescribe San Zi Yang Qin Tang as part of bespoke herbal formulas from pharmaceutical-grade granules sourced from Sun Ten in Taiwan.

TCM pattern

San Zi Yang Qin Tang is prescribed for chronic Phlegm cough with food retention in older adults:

• Cough with copious thin to thick white phlegm
• Wheezing or chest tightness
• Reduced appetite
• Bloating after eating
• Worse in winter or with cold weather
• Older patient, often with chronic respiratory illness
• Tongue — pale, white greasy coat
• Pulse — slippery, possibly soft

Key herbs

1. Bai Jie Zi (white mustard seed, 6-9g) — warms Lung and dries Phlegm in the membranes
2. Su Zi (perilla seed, 6-9g) — descends Lung Qi and stops cough
3. Lai Fu Zi (radish seed, 6g) — transforms Phlegm and resolves food retention

Formula actions

1. Transforms Phlegm
2. Descends Lung Qi
3. Resolves food retention
4. Stops cough and wheeze

Conditions treated

1. Chronic bronchitis in older adults
2. COPD with productive cough
3. Post-viral persistent cough with Phlegm
4. Asthma[13] with Phlegm pattern in older adults
5. Chronic cough in the elderly

Cautions

Persistent productive cough needs medical assessment, especially in smokers and older adults, to exclude lung cancer, TB and other serious conditions.

Not appropriate for Yin-deficient dry cough or Heat-pattern cough with yellow phlegm.

Use cautiously in pregnancy.

Always consult a qualified Chinese herbalist registered with the RCHM.

Prefer to be treated from home? Chinese herbal medicine online consultations are available throughout the UK and worldwide.

Frequently asked questions about San Zi Yang Qin Tang

What is San Zi Yang Qin Tang used for?

San Zi Yang Qin Tang is used for chronic productive cough with copious phlegm in older adults — including chronic bronchitis, COPD with productive cough, persistent post-viral cough, and Phlegm-pattern asthma. It is particularly suited to elderly patients who cannot tolerate stronger Phlegm-resolving formulas. Not appropriate for dry cough, Yin-deficient cough, or Heat-pattern cough with yellow phlegm.

How does San Zi Yang Qin Tang work?

The three seeds work synergistically on different aspects of chronic phlegm-cough. Bai Jie Zi warms the Lung and dries Phlegm sitting in the membranes; Su Zi descends rebellious Lung Qi and stops the cough itself; Lai Fu Zi transforms Phlegm and resolves the food retention that frequently accompanies it in older patients. The mildness of the seeds (as opposed to stronger Phlegm-purging herbs) is what makes it tolerable for long-term use.

Is San Zi Yang Qin Tang safe for elderly patients?

Yes — this formula was specifically designed for elderly patients. The three seeds are mild, food-grade botanicals (mustard, perilla and radish seeds) chosen precisely because they resolve Phlegm without depleting Qi. It can be used over several weeks to months in chronic respiratory illness under the supervision of a qualified RCHM herbalist.

How long does San Zi Yang Qin Tang take to work?

For chronic productive cough most patients notice an improvement in phlegm production and ease of expectoration within 2–3 weeks. Full benefit in COPD or chronic bronchitis typically requires 6–12 weeks of daily granule treatment, often in combination with Spleen-tonifying herbs to address the underlying production of Phlegm.

When should San Zi Yang Qin Tang not be used?

Avoid in Yin-deficient dry cough (no phlegm), Heat-pattern cough with yellow or green phlegm, and acute febrile cough. Persistent productive cough in older adults — especially smokers — needs medical assessment first to exclude lung cancer, TB and other serious causes. Use cautiously in pregnancy. The formula must be prescribed by a qualified herbalist after pattern diagnosis, not self-prescribed.

References

[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.

[13] Shergis JL, Wu L, Zhang AL, Guo X, Lu C, Xue CC. Herbal medicine for adults with asthma: A systematic review. J Asthma. 2016 Aug;53(6):650-9. https://doi.org/10.3109/02770903.2015.1101132. PMID: 27172294.