Dampness-Draining Formulas

胃苓汤 · Wèi Líng Tāng

Wei Ling Tang

Combination of Ping Wei San and Wu Ling San. Addresses Cold-Damp obstructing the Middle Jiao with concurrent water retention, producing diarrhea, distension, nausea and scanty urine.

View formula profile →

Last reviewed August 2026

Formula CategoryDampness-Draining Formulas

Primary PatternDampness

Primary FunctionDry Middle Damp, promote urination, strengthen Spleen

Primary Therapeutic PrincipleDry Dampness, strengthen the Spleen, promote urination and regulate Qi

Main HerbsAtractylodes Rhizome · Magnolia Bark · Tangerine Peel · White Atractylodes Rhizome · Poria / Hoelen · Polyporus · Alisma Rhizome · Cinnamon Twig · Licorice Root

Classical SourceCombination of Ping Wei San + Wu Ling San (traditional)

Why This Formula?

Traditionally selected when Middle-Burner dampness and lower-burner fluid retention occur together, with distension, loose stools and scanty urination — combining what Ping Wei San does for damp in the middle with what Wu Ling San does for water below, neither of which alone covers both.

Overview

What Is Wei Ling Tang?

1. Origin Background

Wei Ling Tang, also known as Stomach-Calming Poria Decoction, is a classical combination formula that merges Ping Wei San and Wu Ling San. Designed to dry dampness, strengthen the spleen, promote urination, and harmonize the stomach, it addresses the pattern of damp obstruction in the middle burner accompanied by water retention.

This formula is primarily used for abdominal distension and fullness, loose stools or diarrhea, scanty urination, a heavy body sensation, and a thick greasy tongue coating. It remains an important prescription in Traditional Chinese Medicine for treating spleen deficiency with damp accumulation and internal water retention.

2. Digestive System Issues

Wei Ling Tang is a very popular choice for many common stomach and gut problems.

Chronic Gastritis: If you deal with long-term stomach inflammation and feel symptoms like persistent bloating, nausea, a lack of appetite, and a thick, "fuzzy" coating on your tongue, this formula can help clear the heaviness.
Chronic Enteritis (Intestinal Issues): For those who suffer from frequent diarrhea, stomach cramps, and loose stools, this formula works by drying up the excess moisture in the intestines and getting your digestion back on track.

3. Urinary and Fluid Issues

This formula is also useful for when your body is "holding on" to too much water.

Edema (Swelling): If you have puffiness in your arms or legs, find it difficult to pee, or feel a heavy distension in your belly, it is often a sign of "dampness overload."
How it helps: By improving the function of your Spleen and Stomach and promoting urination, Wei Ling Tang helps your body flush out that extra water weight and reduces swelling.

4. Skin Conditions (Dermatology)

Traditional Chinese Medicine often looks at the skin as a reflection of what is happening inside the digestive system.

Eczema: If your eczema is of the "weeping" or "oozing" type—meaning the skin feels damp, itchy, and might leak fluid—this formula can be part of the solution.
How it helps: It addresses the root of the problem by clearing the "dampness" from your internal systems. By strengthening your Spleen and Stomach and removing the excess moisture, it helps stop the itching and dries up the skin irritation from the inside out.

How It Works

Herb Composition (Sovereign / Minister / Assistant / Envoy)

1. The Leader (Monarch Herb) — Cang Zhu

Cang Zhu (Atractylodes Lancea) is a warm, pungent herb that focuses directly on your Spleen and Stomach. It is the core ingredient of Wei Ling Tang.

Drying Out the Dampness: When your digestive system feels "swamped" or heavy due to moisture (dampness), your body can't process food correctly. Cang Zhu acts like a sponge, drying up that excess moisture.
Waking Up the Spleen: Its strong, aromatic scent helps "awaken" the Spleen, getting your internal engine running again so you can digest food properly and feel less sluggish.

2. The Deputy (Minister Herb) — Hou Po

Hou Po (Magnolia Officinalis) is a warm and bitter herb that helps the leader by getting your energy (Qi) moving.

Relieving the Bloat: If you feel "stuck," bloated, or full after eating, it is usually because your energy isn't flowing. Hou Po pushes that energy through, clearing out the heavy, "stuffed" feeling in your midsection.
Double Action: While it moves energy, it also helps Cang Zhu dry out dampness, making sure your digestive tract feels light and comfortable.

3. The Helpers (Assistant Herbs) — Chen Pi and Ze Xie

These two herbs help the leaders by approaching the problem from different angles:

Chen Pi (Tangerine Peel): This herb is great for regulating your energy and clearing out "phlegm" or sticky fluids. It helps the whole formula work more smoothly and keeps your stomach feeling settled.
Ze Xie (Alisma): While the other herbs "dry" the dampness, Ze Xie acts like a drain. it flushes excess water out of your body through your urine.
The Strategy: By combining drying (Cang Zhu) and draining (Ze Xie), the formula makes sure that dampness is removed quickly and doesn't come back.

4. The Support Team (Adjuvant & Guide Herbs) — Gan Cao, Fu Ling, and Bai Zhu

These herbs ensure the formula is balanced and gentle on your body:

Fu Ling (Poria) and Bai Zhu (Atractylodes Macrocephala): These two work with Ze Xie to strengthen the "draining" effect while also giving your Spleen a much-needed energy boost. They help your body recover its natural strength.
Gan Cao (Licorice): Known as the "peacemaker," Gan Cao harmonizes all the other herbs. It makes the formula less harsh and protects your stomach lining.
The Result: This team ensures that while the formula is busy clearing out the "bad" moisture, your "good" energy is protected and supported.

Symptoms Traditionally Associated

Clinical Presentation in TCM

1. What’s Going Wrong? (Pathogenesis Analysis)

The main problem that Wei Ling Tang (Weiling Decoction) fixes is "dampness overload" in the Spleen and Stomach. Think of your Spleen and Stomach as the body’s water management center.

The Cause: If you are exposed to cold, damp weather, or if you eat too many raw and cold foods, your water management system can break down.
The Traffic Jam: When water gets stuck inside, it creates a "damp" blockage. This prevents your digestive energy from moving up and down correctly.
The Result: You end up with symptoms like a bloated belly, feeling nauseous, vomiting, or having watery diarrhea. This formula targets that blockage to get everything moving again.

2. What the Formula Does (Actions)

Wei Ling Tang is designed to clear out excess moisture and get your stomach back in sync.

Drying and Draining: By combining herbs like Cang Zhu, Hou Po, Fu Ling, Bai Zhu, and Ze Xie, it acts like a high-powered sponge and a drain at the same time. It dries up the internal moisture and flushes the rest out.
Settling the Stomach: It calms the "upward" energy that causes nausea and vomiting, helping your stomach feel settled and light.
Reducing Swelling: It helps your body process fluids better, which is great for getting rid of extra water weight or puffiness (edema).

3. Who This Formula Is For (Indications)

This formula is traditionally used for digestive issues caused by too much moisture. You might need it if you have:

Digestive Trouble: Frequent loose stools or diarrhea, especially if you also feel very bloated and have no appetite.
Swelling and Fluid Retention: Puffiness in your arms and legs (edema) or finding it difficult to pee.
Cold-Damp Signs: A dull stomach ache, feeling sick to your stomach, or noticing a thick, white, greasy coating on your tongue.
Skin Issues: Because it clears dampness from the inside out, it is also sometimes used as part of a plan to treat certain types of eczema that look "weeping" or fluid-filled.

Formula Analysis

The Mechanism in Classical Theory

1. Drying Dampness and Strengthening the Spleen

Cang Zhu (Atractylodes Lancea) and Bai Zhu (Atractylodes Macrocephala) are the heart of this formula. They work together to fix your digestion from two sides:

The Deep Clean: Cang Zhu is a powerful drying herb. It acts like a sponge to soak up the "dampness" that makes you feel heavy and bloated.
The Power Up: Bai Zhu focuses on boosting your Spleen’s energy (Qi). It gives your digestive system the strength it needs to work again.
The Result: By drying the excess moisture while simultaneously strengthening your internal "engine," this pair treats both the symptoms and the root cause, making sure the dampness doesn't come back.

2. Moving Energy and Settling the Middle

Hou Po (Magnolia Bark) and Chen Pi (Tangerine Peel) focus on getting your internal "traffic" moving again.

Unblocking the Flow: When energy (Qi) gets stuck in your stomach, you feel bloated and full. Hou Po pushes this stuck energy through, quickly relieving that tight, uncomfortable feeling in your belly.
Smoothing the Path: Chen Pi helps regulate this energy flow and supports your Spleen. Together, they make sure your digestive system runs smoothly, clearing up the discomfort caused by stagnant energy.

3. Draining Excess Water

Fu Ling (Poria), Bai Zhu, and Ze Xie (Alisma) are the "drainage team" of the formula.

The Drain Pipe: Ze Xie is the specialist for urination. It gathers the excess water in your body and flushes it out through your urine.
Supportive Draining: Fu Ling and Bai Zhu support this process by strengthening the Spleen, which is responsible for managing fluids.
The Result: This team effectively removes water weight and stops diarrhea by clearing out the excess "swampiness" in your system.

4. Harmonizing the Team

Gan Cao (Licorice Root) is the "peacemaker" in Wei Ling Tang.

Balancing the Herbs: Because this formula contains many strong drying and moving herbs, Gan Cao acts as a buffer. It makes sure all the ingredients work together as a team without being too harsh on your system.
Extra Support: While it harmonizes the formula, it also gives a small boost to your Spleen energy, ensuring your stomach stays protected while the other herbs clear out the dampness.

How This Formula Compares

Clinical Comparison Table

Compare	Wei Ling Tang	Wu Ling San	Ping Wei San	Yin Chen Wu Ling San
Primary Function	Dry Middle Damp, promote urination, strengthen Spleen	Promote urination, drain Dampness, warm Yang	Dry Damp, strengthen Spleen, move Qi	Drain Damp, promote urination, resolve jaundice
Formula Category	Dampness-Draining Formulas	Dampness-Draining Formulas	Dampness-Draining Formulas	Dampness-Draining Formulas
Typical TCM Pattern	Dampness	Dampness	Dampness	Dampness
Main Conditions	Diarrhea, Bloating, Stomach Discomfort, Poor Appetite, Edema	Edema, Frequent Urination, Damp Constitution	Bloating, Poor Appetite, Stomach Discomfort, Diarrhea, Damp Constitution	Edema, Damp Constitution, Frequent Urination
Main Herbs	Atractylodes Rhizome · Magnolia Bark · Tangerine Peel · White Atractylodes Rhizome · Poria / Hoelen · Polyporus · Alisma Rhizome · Cinnamon Twig · Licorice Root	Alisma Rhizome · Poria / Hoelen · Polyporus · White Atractylodes Rhizome · Cinnamon Twig	Atractylodes Rhizome · Magnolia Bark · Tangerine Peel · Fresh Ginger · Jujube / Chinese Date · Honey-fried Licorice	Virgate Wormwood · Alisma Rhizome · Poria / Hoelen · Polyporus · White Atractylodes Rhizome · Cinnamon Twig
Classical Source	Combination of Ping Wei San + Wu Ling San (traditional)	Shang Han Lun (Zhang Zhongjing, Eastern Han)	Tai Ping Hui Min He Ji Ju Fang (Song dynasty)	Jin Gui Yao Lue (Zhang Zhongjing, Eastern Han)

How to tell them apart

Wei Ling Tang combines middle-jiao damp-drying with lower-jiao water draining. Wu Ling San focuses more on fluid transformation. Ping Wei San alone is for pure Middle Damp without prominent urinary symptoms. Yin Chen Wu Ling San adds jaundice-resolving action.

For educational reference only, based on traditional pattern differentiation — not a substitute for professional advice.

Clinical Modifications

Clinical Modifications for Wei Ling Tang

1. If Diarrhea is Severe

If you are dealing with very frequent or watery stools, extra "binding" and strengthening herbs can be added to the formula to help firm things up:

Shan Yao (Chinese Yam): This herb is excellent for nourishing the Stomach and Spleen while providing a gentle "tonifying" effect to stop diarrhea.
Qian Shi (Gorgon Fruit): This herb acts as an astringent, meaning it helps "lock in" fluids and energy, making it very effective for stopping chronic loose stools.
The Result: Adding these two helps the body regain control over its digestion, ensuring that nutrients are absorbed rather than lost.

2. If Swelling (Edema) is Obvious

When fluid retention is a major concern—such as having very swollen ankles or difficulty peeing—we can add more powerful "drainage" herbs to the mix:

Che Qian Zi (Plantain Seed): This is a classic herb for clearing heat and pushing excess water out through the urine.
Hua Shi (Talc): This mineral herb helps "slick" the water passages, making it easier and more comfortable to pee while clearing out internal heat.
The Result: These herbs turn up the power of the formula’s diuretic effect, helping you shed excess water weight and reduce puffiness quickly.

3. If Bloating and Gas are Severe (Qi Stagnation)

If your main complaint is a feeling of intense pressure in your upper stomach, frequent burping, or "stuck" gas, extra energy-moving herbs are needed:

Mu Xiang (Costus Root): This is one of the best herbs for moving energy in the digestive tract. It specifically helps stop the dull, distending pain caused by gas.
Sha Ren (Amomum Fruit): This aromatic herb "wakes up" the Spleen and helps move energy downward, which stops nausea and settles a bloated stomach.
The Result: By adding these, the formula becomes much more effective at clearing out the "pressure" in your midsection and getting your digestive "traffic" moving again.

Modern Research

What the Science Suggests

1. What Science Says About the Herbs

Modern pharmacological studies have shown that the ingredients in Wei Ling Tang work in several ways to improve your health:

Improving Digestion: Herbs like Cang Zhu (Atractylodes Lancea) and Hou Po (Magnolia Bark) help regulate how your gut moves. They promote healthy contractions in the digestive tract, which helps food move through more efficiently and strengthens your overall digestive power.
Flushing Excess Water: The diuretic herbs in the formula, such as Fu Ling (Poria) and Ze Xie (Alisma), are proven to increase urine output. This helps your body manage its water metabolism and get rid of unwanted fluid buildup.
Fighting Inflammation: Research also shows that Wei Ling Tang has anti-inflammatory and antibacterial properties. This helps calm the gut and reduce symptoms caused by internal irritation or low-grade infections.

2. Proven Results in Clinical Studies

Clinical research has put this ancient formula to the test, confirming that it is highly effective for "dampness" issues:

Fixing Chronic Diarrhea: In trials involving patients with long-term diarrhea, Wei Ling Tang significantly improved symptoms. It helped firm up stools, reduced the number of bathroom trips, and was found to be very safe for regular use.
Reducing Swelling: For patients dealing with water retention (edema), clinical data shows the formula helps the body shed excess water by regulating how it processes fluids, leading to a visible reduction in swelling.

3. Modern and Convenient Formats

As technology advances, the way people take Wei Ling Tang is changing to fit a modern lifestyle:

New Options: While the traditional boiled tea (decoction) and concentrated granules are still popular, you can now find the formula in easy-to-carry capsules and tablets.
Consistency and Quality: These new formats make it much easier for patients to take their medicine regularly, especially when traveling. Scientists have ensured that these modern versions are just as stable and effective as the traditional tea, giving you more high-quality options for your treatment.

Safety

Safety Considerations

1. Dietary Restrictions & Special Populations

While taking Weiling Decoction, avoid raw/cold and greasy foods that damage spleen‑stomach yang, increase dampness, or hinder digestion. Use cautiously in pregnancy—its qi‑circulating and blood‑activating effects may affect the fetus—and in spleen‑stomach deficiency‑cold, where dose or formula should be adjusted to avoid further yang depletion.

2. Monitoring & Follow‑up

Monitor symptoms during treatment; if diarrhea worsens, fever or new signs appear, seek medical evaluation and adjust the treatment plan—do not self‑medicate or continue the formula blindly.

Available Products

Where to Get It

HJMEDICAL Hoi Tin Wei Ling Tang (Stomach-Poria Combined Decoction) 5:1 Concentrated Granules $30.50

HJMEDICAL Hoi Tin Ping Wei San (Calm the Stomach Powder) 5:1 Concentrated Granules $22.15

HJMEDICAL Nong's Ping Wei San (Calm the Stomach Powder) 5:1 Concentrated Granules $60.88

HJMEDICAL Hoi Tin Wu Ling San (Five-Ingredient Powder with Poria) 5:1 Concentrated Granules $22.15

HJMEDICAL Nong's Wu Ling San (Poria Five Powder) 5:1 Concentrated Granules $51.25

FAQ

Questions About Wei Ling Tang

Q1: What are the actions of Wei Ling Tang?

Wei Ling Tang has the actions of strengthening the Spleen and drying Dampness, promoting urination and resolving water retention, and regulating Qi to harmonize the Stomach. It is a combination of Ping Wei San and Wu Ling San, designed for Cold-Damp obstructing the Middle Jiao with concurrent water accumulation.

Q2: Which modern diseases is Wei Ling Tang suited to?

Modern TCM clinical practice commonly applies it to individuals whose pattern differentiation falls within Cold-Damp obstructing the Spleen with water retention, including acute or chronic gastroenteritis with watery diarrhea, edema accompanied by digestive sluggishness, certain cases of ascites, and fluid retention with abdominal distension.

Q3: Is Wei Ling Tang suitable for improving watery diarrhea and abdominal bloating?

For presentations of watery diarrhea, abdominal distension or pain, poor appetite, scanty urine, mild edema, heavy limbs, and a thick white greasy tongue coating — in those whose pattern differentiation confirms Cold-Damp in the Middle Jiao with water retention — TCM commonly applies Wei Ling Tang as an adjunct. It cannot replace standard medical treatment.

Q4: Who should not take Wei Ling Tang?

Those with Yin deficiency, Blood deficiency, Damp-Heat patterns, or thirst due to true Heat are generally not suitable. The formula is warm and drying and can further injure fluids in deficient or Heat patterns. Use should be assessed by a qualified TCM physician.

Q5: How does Wei Ling Tang combine the actions of Ping Wei San and Wu Ling San?

Ping Wei San dries Dampness, moves Qi, and strengthens the Spleen to address digestive stagnation and turbidity. Wu Ling San promotes urination and transforms Qi to drain excess water. Together they simultaneously resolve Middle Jiao Dampness and lower-body water retention.

Q6: Can Wei Ling Tang help with edema that occurs together with diarrhea?

Yes, when both symptoms arise from the same pattern of Spleen Dampness failing to transform fluids, leading to water retention and downward leakage as diarrhea. The formula strengthens the Spleen while promoting proper fluid metabolism through urination.

Q7: What are the main ingredients of Wei Ling Tang?

The formula combines Ping Wei San ingredients (Cang Zhu, Hou Po, Chen Pi, Gan Cao) to dry Dampness and move Qi with Wu Ling San ingredients (Ze Xie, Fu Ling, Zhu Ling, Bai Zhu, Gui Zhi or Guan Gui) to promote urination and warm Yang for fluid transformation.

Q8: Is Wei Ling Tang suitable for long-term use?

It is generally used for a defined course under professional supervision until the Dampness and water retention resolve. Because of its warm, drying, and diuretic nature, prolonged use requires monitoring to avoid injuring Yin or fluids.

Q9: How does Wei Ling Tang differ from Wu Ling San alone?

Wu Ling San primarily focuses on promoting urination and transforming Qi for water accumulation (often with thirst and urinary difficulty). Wei Ling Tang adds the Dampness-drying and Qi-moving actions of Ping Wei San, making it more suitable when digestive symptoms such as bloating, poor appetite, and watery diarrhea are prominent alongside fluid retention.

Q10: What lifestyle advice supports the use of Wei Ling Tang?

Avoiding cold, raw, greasy, or overly sweet foods, keeping the abdomen warm, and eating regular, easily digestible meals help support Spleen function and reduce Dampness accumulation. Professional guidance remains essential for safe and effective use.

FAQ

General Questions

How do I choose the right formula?

TCM formulas are traditionally selected according to individual pattern differentiation rather than by symptom alone. If you're not sure which formula fits your presentation, take our AI Assessment below for a personalized starting point, then confirm with a qualified TCM practitioner.

What are concentrated herbal granules?

Concentrated herbal granules are made by decocting raw herbs, then extracting and concentrating the resulting liquid into a fine granule or powder form. This preserves the same active compounds as a traditional decoction while making the herbs far easier to store, measure, and prepare.

How should I take these products?

Dissolve the recommended amount of granules in hot water, stir until fully dissolved, and drink while warm — following the dosage and frequency advised by your TCM practitioner or as stated on the product packaging.

Are concentrated herbal granules equivalent to traditional decoctions?

Concentrated granules are produced from the same herbs and processed to retain their active compounds, so they are traditionally regarded as a convenient alternative to decoctions rather than a different remedy. Some practitioners note subtle differences in strength or absorption between the two forms, so your TCM practitioner may adjust dosage accordingly.

Are your products authentic?

Yes. HJMEDICAL sources its concentrated granules exclusively from established, reputable manufacturers such as Nong's and Hoi Tin, both long-standing names in the TCM granules industry, with GMP compliance stated directly on their packaging.

Are HJMEDICAL products manufactured under GMP standards?

HJMEDICAL sources its concentrated granules from established, reputable manufacturers such as Nong's and Hoi Tin, both long-standing names in the TCM granules industry. GMP compliance for these products is stated directly on their packaging.

Do you ship internationally?

Yes — we ship worldwide! Every order goes out via Hong Kong Post, and your exact shipping cost and estimated delivery time for your address are calculated and shown right at checkout, so there are never any surprises. We also offer free shipping once your order reaches our free-shipping threshold, so it's easy to stock up on your favorite formulas and save.

Can I take more than one formula at the same time?

Some formulas are traditionally combined, while others overlap or counteract each other. We recommend checking with a qualified TCM practitioner before combining formulas, especially if you are already taking other medication.

Are these products suitable during pregnancy or breastfeeding?

Some TCM formulas are not suitable during pregnancy or breastfeeding. Please consult a qualified TCM practitioner or your doctor before use if you are pregnant, trying to conceive, or nursing.

Do these products replace medical treatment?

No. These products are traditional herbal supplements intended to support wellbeing according to TCM principles — they are not a replacement for professional medical diagnosis or treatment. Please consult a qualified TCM practitioner or licensed healthcare provider before starting, stopping, or combining any treatment, especially if you have a chronic condition.

Medical Disclaimer

For general TCM education only — not medical advice. Consult a qualified TCM practitioner or licensed healthcare provider before use, especially if pregnant, nursing, on medication, or managing a chronic condition.

Not sure which formula is right for you?

Take the AI Assessment