Ping Wei San — Calm the Stomach Powder

On this page

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

Overview

Ping Wei San — Calm the Stomach Powder — is the foundational formula in Chinese herbal medicine for drying Dampness and strengthening the Spleen and Stomach. Dating to the Song Dynasty, its four simple herbs create a powerful formula that directly targets Damp obstructing the Middle Jiao — one of the most common pathological patterns in clinical practice, particularly in patients who consume a diet high in damp-generating foods or who live in damp environments. It serves as the base from which dozens of derivative Damp-resolving formulas are built.

TCM pattern

Prescribed for Damp obstructing the Spleen and Stomach (Middle Jiao), characterised by: a sensation of fullness and distension in the epigastrium and abdomen, nausea, heavy feeling in the body and limbs, fatigue, loose stools, a bland or absent sense of taste, a swollen tongue with thick greasy white coating, and a slow, slippery pulse.

Key herbs

1. Cang Zhu (Atractylodes lancea rhizome) — the most potent Damp-drying herb in TCM; strongly dries Dampness and strengthens the Spleen
2. Hou Po (Magnolia officinalis bark) — moves Qi, dries Dampness and reduces distension; particularly effective for bloating and fullness
3. Chen Pi (aged Citrus reticulata peel) — regulates Qi, dries Dampness and harmonises the Middle Jiao
4. Zhi Gan Cao (honey-fried Glycyrrhiza root) — harmonises the formula and moderates the drying herbs

Formula actions

1. Dries Dampness
2. Transforms Phlegm
3. Moves Qi
4. Strengthens the Spleen and Stomach

Conditions treated

1. Bloating, abdominal distension and epigastric fullness from Damp obstructing the Middle Jiao
2. Nausea and poor appetite from Spleen-Damp
3. Digestive sluggishness and heavy limbs after eating damp-generating foods
4. IBS with Damp predominance
5. Long COVID with Phlegm-Damp brain fog and digestive symptoms

Warm and drying — use with caution in Yin deficiency or where fluid deficiency is present.

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.