Yi Wei Tang

What Yi Wei Tang is for

The skin this formula addresses has lost its moisture suddenly rather than slowly: dry, tight and inelastic, as though the surface has been drained. It appears in the recovery phase after a feverish illness, or over skin that is healing from a burn once the injury itself has been treated. The formula restores the fluids the tradition treats as the source of the body's moisture, and it does so gently enough to be taken while the body is still recovering.

The surface looks dry in a flat, even way: no redness, no scaling edge, just a fine tightness and a loss of the spring that lets skin lift and settle back. It creases and stays creased, feels rough under the fingers, and looks dull rather than inflamed. The dryness is recent, and it followed an illness that consumed the body's fluids, or an injury that stripped the surface and left the tissue to rebuild. There is little itch and no weep, which is what separates it from the dry eruptive patterns.

Sheng Di Huang, Mai Dong, Bei Sha Shen and Yu Zhu all nourish and generate fluids, and all four are light and non-greasy, so moisture is supplied without burdening a body that is still recovering. Bing Tang sweetens the decoction and helps the fluids be taken up rather than passed through. None of the herbs is warming or drying, which is why the formula can be given soon after an illness when richer tonics would sit heavily.

It suits the recovery phase and not deep chronic Yin depletion, where a fuller tonic is needed over a longer course. It is stopped if Dampness appears, since a greasy coat means the body is retaining fluid rather than lacking it, and it is not for cold deficiency. Dryness after a burn belongs to the recovery stage only: the burn itself needs medical care, and a surface that is not settling needs review rather than a longer course.

Actions

• Nourishes Stomach Yin
• Generates fluids
• Moistens dryness of the mouth, throat and skin
• Supports recovery after fever

Properties

• Taste and temperature: Predominantly sweet and slightly cold. Sweet and moistening to generate fluids, cold to clear residual heat.
• Organs: Stomach, Lungs
• Channels: Stomach, Lung

The pattern behind it

The pattern is Stomach Yin and fluid deficiency, usually after a febrile illness. The Stomach is the source of the body's moisture, so when its fluids are consumed the mouth dries, the tongue loses its coat and the skin loses suppleness. The formula restores those fluids gently.

Composition

The herbs in Yi Wei Tang, with their role and dose.

Patterns it treats

How the formula is built

Four moistening herbs and a little sweetness. All of them nourish and generate fluids, with a light, non-greasy quality that suits the Stomach, which is why the formula can be taken during recovery without burdening digestion.

Skin conditions it is used for

Where this formula appears in the skin conditions of the library.

Preparation and use

Decocted in water and taken warm, in two divided doses.

Modifications

• If the dryness is severe, more moistening herbs are added.
• If residual Heat remains, gentle cooling is added.
• If the appetite is poor, the formula is given in smaller doses more often.
• If Dampness appears, the formula is stopped.

Timing

Taken warm in two divided doses.

Duration

One to four weeks for post-febrile recovery, and longer for chronic dryness under guidance.

Diet while taking it

Moistening food and fluids in small sips; avoid drying food, alcohol and heavy spice.

Safety

Interactions

No major interaction is recorded in the reference.

Pregnancy

Generally considered safe in pregnancy, as all five ingredients are food-like or gentle, though professional guidance is appropriate.

Breastfeeding

Considered acceptable under professional guidance.

Children

Used in children with reduced dose for dryness after fever.

Before you use it

Recorded from the classical record and rewritten in this project's own words. Educational only: not a prescription, and burns need medical assessment.

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.

Selected PubMed records

Real PubMed records for the modern, non-TCM discussion of this formula. They are references, not a claim that the formula is proven for any skin condition.

• Molecular and non-molecular approaches to etiologic diagnosis of gastroenteritis.. Advances in clinical chemistry, 2020. PMID: 32951639.

Origin and history

Wen Bing Tiao Bian (温病条辨, Systematic Differentiation of Warm Diseases) by Wu Jutong, Qing dynasty, 1798.

Yi Wei Tang appears in Wu Jutong's 1798 treatise on warm diseases, written for the Stomach Yin damage that follows prolonged fever. Its gentle, food-like herbs made it a standard formula for recovery, and the same moisture restoration is what dry and damaged skin needs after illness or burns.

Classical record

Related formulas

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.