Liu Yi San — Six-to-One Powder

On this page

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

Overview

Liu Yi San — the “Six-to-One Powder” — is from Liu Wansu’s Jin-dynasty Shang Han Biao Ben. The name describes the proportion: six parts Hua Shi (talc) to one part Gan Cao. It is the simplest classical answer to summer Heat with Damp — Hua Shi drains Damp-Heat downward through urination while Gan Cao protects fluids. The formula is widely used as a base remedy for heatstroke, summer thirst, scant dark urine and acute Damp-Heat in the lower burner (cystitis, urinary tract infection).

I prescribe Liu Yi San as part of bespoke herbal formulas from pharmaceutical-grade granules sourced from Sun Ten in Taiwan.

TCM pattern

Liu Yi San is prescribed for summer Heat with Damp affecting the lower burner:

• Fever, restlessness, irritability in hot weather
• Thirst, dry mouth, sweating
• Scant dark yellow urine
• Urinary frequency, urgency, burning
• Possibly diarrhoea with Damp-Heat
• Tongue — red, yellow coat
• Pulse — slippery, rapid

Key herbs

1. Hua Shi (talc) — chief; clears summer Heat and drains Damp through urination
2. Gan Cao — clears Heat; resolves toxin; protects fluids; harmonises

Formula actions

1. Clears summer Heat
2. Resolves Damp through urination
3. Generates fluids and quenches thirst

Conditions treated

1. Mild heatstroke or summer Heat illness
2. Acute uncomplicated cystitis with Damp-Heat pattern
3. Summer dehydration with scant dark urine
4. Mild summer diarrhoea with Damp-Heat
5. Heat rash or prickly heat in hot weather
6. As a base formula with other ingredients added for stronger summer Heat clearance (Bi Yu San, Yi Yuan San)

Cautions

Severe heatstroke (core temperature above 40°C, confusion, collapse) is a medical emergency — call 999, do not rely on herbs.

Acute pyelonephritis (fever, loin pain, vomiting) requires urgent antibiotics — herbs are supportive only.

Hua Shi should be wrapped during traditional decoction; granule form bypasses this issue.

Not appropriate for Yang-deficient cold patterns or pure Yin-deficient thirst without summer Heat.

Always consult a qualified Chinese herbalist registered with the RCHM.

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