Zhi Sou San

What is Zhi Sou San?

Zhi Sou San — literally 'Stop Coughing Powder' — is a seven-herb formula first recorded in the Qing dynasty medical text Yi Xue Xin Wu (1732) by Cheng Guopeng. It was specifically designed for the type of cough that lingers after an external illness like a cold or flu — when the main infection is gone but the airways remain irritated and sensitive. The formula strikes a balance between dispersing what is stuck and nourishing what has been depleted.

How does Zhi Sou San work?

The herbs are thought to work together to open and soothe the airways, gently loosen phlegm, calm airway spasm, and reduce irritation in the throat and bronchial tubes. Bai Bu and Zi Wan are the core cough-relieving herbs and are traditionally regarded as having antitussive and expectorant actions, though robust clinical evidence in humans remains limited. Jie Geng is understood in traditional practice to direct the other herbs upward to the lungs and may help thin and move phlegm. Jing Jie is traditionally used to dispel remaining external irritants, Chen Pi is thought to support smooth airflow and reduce phlegm formation, and Gan Cao is used to soothe irritation and harmonize the formula.

What forms does Zhi Sou San come in?

Granules dissolved in hot water are the most practical modern form and preserve the full formula's profile. Ready-made tablets and capsules (patent medicines) are convenient for travel or daily use. Traditional decoction — boiling the raw herbs as a tea — remains the gold standard in clinical TCM practice for customization. Powder form is less common in the West but is the original preparation method.

Where it comes from:

Zhi Sou San was formulated by Dr. Cheng Guopeng and published in his 1732 text Yi Xue Xin Wu ('Medical Revelations'). He created it as a gentle, universally applicable cough formula — noting that most coughs, regardless of origin, involve some degree of lingering external pathogen and airway irritation. It became one of the most widely taught and prescribed formulas in Chinese herbal medicine education and remains a foundation formula in TCM training globally today.

What does Zhi Sou San help with?

• Lingering cough after cold or flu: This is the formula's traditional primary application — the type of cough that drags on for weeks after a person otherwise feels better. In traditional practice, the herbs are used to calm an overreactive cough reflex and support the airways' recovery, though controlled clinical trials confirming this effect are lacking.
• Dry, itchy, or tickling throat cough: The licorice and Aster root components have traditionally been used to soothe irritated mucous membranes in the throat and upper airways. Practitioners have long applied Zhi Sou San when the cough presents as a persistent, irritating tickle rather than productive congestion, though this is based on traditional observation rather than clinical study.
• Cough with white or clear phlegm: Jie Geng and Bai Qian are traditionally used together to thin phlegm and support the body's ability to clear it. Traditional guidance holds this formula is more suited to mild, non-thick mucus — thick yellow or green phlegm is generally considered in traditional practice to call for a different formula.
• Acute bronchitis (mild to moderate): Several herbs in the formula are thought to have anti-inflammatory and soothing actions on the airway lining, and the formula has traditionally been used to address cough and irritation consistent with mild bronchitis. Any reports of use in clinical settings in China should be considered preliminary and observational only, as rigorous controlled trial evidence is not established.
• Chronic bronchitis (supportive care): In traditional practice, the formula has been used as part of a broader care approach to help ease the frequency and intensity of coughing in people with chronic bronchitis. This is observational in nature, and the formula is traditionally considered more appropriate during milder phases rather than acute flare-ups.
• Cough variant asthma (mild cases): Modified versions of Zhi Sou San have traditionally been applied in cases where cough, rather than wheeze, is the dominant symptom. Any reports of encouraging outcomes are preliminary and observational only; this formula should not be substituted for evidence-based asthma management without guidance from a qualified practitioner.
• Upper respiratory tract infections: The formula has traditionally been used to support recovery from upper respiratory infections by addressing the cough and throat irritation that often persist after the acute phase. It is not a substitute for antibiotic treatment where clinically indicated, and its use in this context is based on traditional practice rather than verified clinical trials.
• Throat irritation and hoarseness: Licorice root and Platycodon root have long been used in traditional practice to soothe throat inflammation and support voice recovery after vocal strain or illness. This application is rooted in traditional observation rather than clinical proof, and individuals with persistent hoarseness should seek professional evaluation.

What can Zhi Sou San help prevent?

• Progression from acute to chronic cough when used early in post-infectious recovery

Which foods are rich in Zhi Sou San?

1. Cooked pear
2. Raw honey
3. Fresh ginger tea
4. Daikon radish
5. Warm bone broth

Practical Tips:

Zhi Sou San is an herbal formula, not a compound found in everyday foods. To support its cough-relieving and lung-nourishing effects, focus on foods that soothe and protect the respiratory tract. Pears (especially cooked or steamed) are the top traditional lung-moistening food in Chinese medicine and directly complement this formula. Raw honey mixed into warm water soothes throat membranes and is traditionally valued for its antimicrobial and cough-soothing properties. Ginger tea helps dispel remaining cold or irritation from the airways. Radish (daikon) thins mucus and supports phlegm clearance. Bone broth provides collagen and minerals that support mucosal tissue repair. Avoid cold foods, dairy, and greasy or fried foods during cough recovery — these are traditionally considered phlegm-promoting in Chinese medicine and can slow recovery.

What are the side effects of Zhi Sou San?

• Mild nausea or stomach upset, especially on an empty stomach
• Loose stools or mild diarrhea in sensitive individuals
• Headache (rare, usually related to Jing Jie component)
• Mild dizziness (uncommon)
• Allergic reactions to individual herbs (rare): stop use if rash, itching, or breathing difficulty occurs
• Prolonged high-dose use of Gan Cao (licorice) may cause water retention or elevated blood pressure

Good to know:

Zhi Sou San has been used safely for nearly 300 years and is considered a gentle, well-tolerated formula. Side effects are uncommon at standard doses and typically resolve on their own. It is best avoided or used under supervision during pregnancy.

How much Zhi Sou San should you take?

• Recommended daily: Granules: 3–6 grams dissolved in hot water, 2–3 times daily. Patent tablets/capsules: follow product labeling (typically 3–4 tablets, 3 times daily). Raw herb decoction: 1 standard formula bag (approx. 100–150g dry herbs) simmered and divided into 2–3 doses.
• Best time of day: Take between meals — morning, midday, and evening dosing is the traditional approach. Warm the granule or decoction preparation — drinking it warm enhances the formula's airway-opening effect.
• With or without food: Best taken 30–60 minutes after meals to reduce any chance of stomach upset and to support absorption. Avoid taking on a completely empty stomach.
• Time to effect: Noticeable cough relief typically within 3–7 days; full resolution of lingering cough usually within 1–2 weeks of consistent use.
• How long to take it: Use for the active cough period — typically 1 to 3 weeks. This formula is designed for acute-to-subacute use rather than indefinite daily supplementation. If cough persists beyond 3 weeks without improvement, reassess with a practitioner. Not intended for long-term continuous use due to the Gan Cao content.