What Ping Wei San is for
The skin picture is greasy, congested and doughy: tissue that looks heavy and dull rather than red or dry, with a shine that does not clear. The explanation is Dampness congesting the middle, which shows in the tissue as congestion, and the powder dries the Dampness and moves the Qi that has stagnated. It is a short course rather than a long treatment.
The skin looks heavy rather than inflamed. It is greasy or doughy to the touch, dull in colour, and congested in a way that reads as sluggishness rather than as a flare. There is no heat in it and no dryness: the surface is oily and slightly puffy, and it stays that way instead of coming and going. Greasy hair and a greasy scalp often belong to the same picture. Where the skin is like this and the tongue carries a thick greasy coat, the tradition reads both as one Dampness.
The tradition explains the congested surface as Dampness that has settled in the middle and shows in the tissue. Cang Zhu dries the Dampness strongly and supports the Spleen; Hou Po and Chen Pi move the Qi so the middle stops stagnating; Gan Cao holds the centre. All three main herbs are warm and drying, which is what makes the formula effective for the congested damp picture and unsuitable for anything dry or depleted. It belongs to short courses, often as the drying half of Wei Ling Tang.
It is not for dry or Yin-deficient skin, where the warmth and drying would take more from a surface that is already short of moisture. It is used for one to two weeks and then reassessed, because prolonged use would dry the body. Candidiasis is treated only as supportive care, where Dampness with a greasy coat underlies recurrence, and needs medical diagnosis and treatment.
Actions
- Dries Dampness and strengthens the Spleen
- Moves Qi and relieves fullness
- Calms the Stomach
- Transforms turbidity
Properties
- Taste and temperature: Predominantly pungent and bitter with a warm quality. Pungent moves Qi, bitter dries Dampness, warmth supports transformation.
- Organs: Spleen, Stomach
- Channels: Spleen, Stomach
The pattern behind it
The pattern is Dampness congesting the Spleen and Stomach. The Dampness produces the fullness, the greasy coat and the heavy head, and it interferes with the transformation of food and fluids. The formula dries the Dampness and moves the Qi, which is why it is used for the congested damp picture rather than for dryness.
Composition
The herbs in Ping Wei San, with their role and dose.
| Role | Herb | Dose | Properties | Why it is there |
|---|---|---|---|---|
| Deputy | Cang Zhu | 9 to 15 g | Warm, Pungent, bitter | Dries Dampness strongly and supports the Spleen, the main drying herb. |
| King | Hou Po | 6 to 9 g | Warm, Bitter, pungent | Moves Qi and dries Dampness, relieving the abdominal fullness. |
| King | Chen Pi | 6 to 9 g | Warm, Pungent, bitter | Moves Qi and dries Dampness in the middle. |
| Gan Cao | 3 to 6 g | Neutral, Sweet | Harmonises the formula and supports the middle. |
Patterns it treats
Damp-Phlegm
Greasy, congested and doughy skin that looks heavy and dull rather than red or dry, often with a shine that does not clear. The Dampness has settled in the middle, so the tissue stays congested until it is dried and the Qi is moved.
How the formula is built
Three herbs dry and move, one supports the middle. Because all three are warm and drying, the formula is effective for the congested damp picture but unsuitable for anything dry or depleted, and it is used in short courses.
Skin conditions it is used for
Where this formula appears in the skin conditions of the library.
Preparation and use
Taken as a powder in warm water, or decocted with ginger and dates.
Modifications
- If the Dampness is accompanied by fluid accumulation, the draining herbs of Wu Ling San are added to make Wei Ling Tang.
- If Cold is present, warming herbs are added.
- If Heat is present, cooling herbs are added.
- If the person is dry or depleted, the formula is not used.
Timing
Taken in two divided doses.
Duration
Short-term use: one to two weeks for acute Dampness, reassessed.
Diet while taking it
Avoid greasy sweet and cold raw food, which increase Dampness.
Safety
Contraindications
Avoid in Yin deficiency and in dry patterns, since the formula is warm and drying. Avoid in pregnancy without guidance.
Interactions
Gan Cao may interact with diuretics, digoxin and corticosteroids.
Pregnancy
Use with caution in pregnancy because Hou Po moves Qi downward.
Breastfeeding
Use only under professional guidance.
Children
Used only with professional supervision.
Before you use it
Recorded from the classical record and rewritten in this project's own words. Educational only: not a prescription.
General safety references
General references for herbal hepatotoxicity and herb-drug interactions; they are not specific to this formula.
- Review article: Herbal hepatotoxicity - an update on traditional Chinese medicine preparations. Alimentary Pharmacology & Therapeutics, 2014. PMID: 24844799.
- Interactions between herbal medicines and prescribed drugs: an updated systematic review. Drugs, 2009. PMID: 19719333.
- Warfarin and food, herbal or dietary supplement interactions: a systematic review. British Journal of Clinical Pharmacology, 2021. PMID: 32478963.
Origin and history
Tai Ping Hui Min He Ji Ju Fang (太平惠民和剂局方, Formulas from the Imperial Pharmacy), Song dynasty, 12th century.
Ping Wei San is one of the standard Dampness formulas of the Song formulary, and it is often combined with draining formulas when fluid has also accumulated. Its short course and drying nature make it a starting point rather than a long-term treatment.
Evidence note
No controlled trial of this treatment in skin conditions was identified for this entry. What is described here rests on the classical and later materia medica record and on traditional clinical use, not on controlled trial evidence, and it is not a prediction of benefit. Where skin-specific research does exist it is linked above.
Common questions
How is it different from Wei Ling Tang?
Wei Ling Tang is this formula combined with a fluid-draining formula. Ping Wei San alone dries Dampness and moves the middle.
Why only a short course?
Because all three main herbs are warm and drying, and prolonged use would dry the body.
Can it help greasy skin?
Where there is a greasy tongue coat and digestive fullness, it can be part of the treatment.
Who should avoid it?
People with dry or Yin-deficient patterns.