Fruits and seedsPhlegm-resolvingTrichosanthis Pericarpium

Gua Lou Pi (Mongolian Snakegourd Peel)

A practical guide to Gua Lou Pi: what it is, how Traditional Chinese Medicine uses it, the classical formulas it appears in, and who should be careful with it.

View Herb Profile →

Last reviewed Oct 29, 2026

Quick Facts

Latin Name	Trichosanthis Pericarpium
Chinese Name & Pinyin	瓜蔞皮 · Gua Lou Pi
Medicinal Part	Fruits and seeds
The item	Gua Lou Pi is the outer peel of the ripe trichosanthes fruit, seeds removed. Gua Lou Ren is not this herb. It usually goes into decoctions or light teas.
Nature and channels	Cold. Sweet, slightly bitter. Enters the Lung and Stomach. Cold sweet slight bitter clears heat-phlegm, regulates qi, and opens the chest.
Pharmacopoeia line	Moistens lung dryness, lowers fire, stops cough, washes away phlegm stagnation, and benefits the throat. Used for cough with sticky phlegm, chest oppression, and stuffy painful chest.
Pattern cues	Thick yellow sputum that is hard to cough up. Stuffy chest after stress or greasy food. Tight chest pain reaching the back.
In this article	Gua Lou Pi versus Gua Lou Ren. Clearing heat-phlegm versus moistening the intestines. Why the tea dose is small. Why pregnancy is a caution. Why chest pain needs a clinic. Who should skip it.

What Is Gua Lou Pi?

Gua Lou Pi (瓜蒌皮; Guā Lóu Pí; Latin: Trichosanthes Pericarpium; English: trichosanthes peel) in the current pharmacopoeia is the outer pericarp of the ripe fruit of Trichosanthes kirilowii or Trichosanthes rosthornii of the Cucurbitaceae family, gathered in autumn when the skin turns from green to yellow, cut open with the seeds removed, then sun-dried; the honey-processed version leans more toward moistening the lung. It is cold, sweet and slightly bitter, enters the Lung and Stomach channels, and its core actions are to clear heat-phlegm, and to regulate qi and open the chest. It usually goes into decoctions or light teas. The usual amount is 6–12 g. It needs no special handling in the pot and is decocted with the other herbs for about fifteen to twenty minutes, not longer, to protect the volatile constituents.

It is not Gua Lou Ren. Gua Lou Ren is the seed — cold and sweet, with a moistening, downward-moving character that moistens lung dryness and lubricates the intestines; it does not open the chest the way the peel does. Gua Lou Pi is clear and dispersing, floating upward and outward to free the chest-diaphragm qi, which is why it fits stuffy chest with sticky phlegm. Use caution in pregnancy. White thin cold-phlegm with aversion to cold is a poor match. Loose stool with a cold weak stomach needs pattern diagnosis. Shortness of breath that worsens after activity is a poor match. Chest pain that radiates to the back or comes with sweating needs a clinic first.

It is used most often for three patterns:

Heat-phlegm cough — thick yellow sputum that is hard to bring up
Chest-diaphragm qi stagnation — stuffy chest, belching, bloating
Chest bi — tight chest pain that may reach the back — seek care

Cold, sweet, and slightly bitter, it is not a daily “chest-clearing peel” to keep increasing. Moving qi when there is no qi stagnation consumes the upright qi and can damage a cold weak stomach.

When heat-phlegm clogs the chest and lungs, or phlegm-turbidity blocks the chest yang, sticky yellow sputum, stuffy chest, and pain reaching the back are common. Gua Lou Pi is cold, sweet, and slightly bitter. It clears phlegm and frees the chest, which is why it appears in Gua Lou Xie Bai Ban Xia Tang (Trichosanthes-Allium-Pinellia Decoction)–type formulas, and in Qing Qi Hua Tan Wan (Qi-Clearing Phlegm-Transforming Pill)–type formulas for phlegm-heat. It disperses more than it tonifies. A cold spleen and stomach, with loose stool and no heat-phlegm, get worse if more is added.

Gua Lou Pi is not a catch-all chest or cough peel. In cold-phlegm, in a cold weak stomach with loose stool, or in pregnancy, using it alone is a poor match. Raw or honey-processed, and whether it belongs in a formula, should be decided by a licensed Chinese medicine practitioner after pattern diagnosis.

Gua Lou Pi: Materia Medica Profile

Identification & Quality Standard

Trichosanthis Pericarpium

Botanical Origin

The dried pericarp of Trichosanthes kirilowii Maxim. or Trichosanthes rosthornii Harms (Cucurbitaceae).

Production Regions

Primarily produced in the Chinese provinces of Shandong, Hebei, Henan, Shanxi, Jiangsu, Zhejiang.

Quality Requirements

Superior material is orange-yellow, thick and unscorched.

Macroscopic Features

Pericarp split into two halves, bowl-shaped, 6~12 cm long, 2~4 cm wide; outer surface orange-yellow or orange-red, lustrous, with occasional residual fruit stalk; inner surface yellowish-white, with reticulate vascular bundles; texture light, brittle; slight fragrance; slightly bitter taste.

Main Regions and Quality Identification

Traditional materia medica and industry experience value the Gua Lou Pi of certain producing areas, but actual quality also depends on variety, harvest time, processing, and storage. The common producing areas include several provinces of eastern and central China. In appearance, good-quality Gua Lou Pi is curled tubular or irregular fragments, with an orange-yellow or light-brownish-yellow outer surface with wrinkles, a pale-yellow inner surface with silky-textured veins, a faint fragrance, and a light, slightly bitter taste. The difference between the raw and the processed is clear: the raw has a harder texture and brighter color — fitting the clearing of heat-phlegm; the honey-processed has a deeper color, a honey luster on the surface, and a slightly softer texture — more fitting moistening the lung. The common look-alikes are the peels of other Cucurbitaceae plants — such as the loofah shell — with a rougher inner surface, no silky texture like Gua Lou Pi, and a fainter odor — distinguish them carefully.

Traditional Properties & Historical Lineage

Nature, Flavour & Channel Tropism

Sweet; ColdLungStomach

1. Records in Classic Materia Medica

Shen Nong Ben Cao Jing: lists the Trichosanthes fruit as "middle grade," without yet clearly distinguishing the peel from the seed — mentioning only that it "governs chest bi and brightens the face" — the chest bi including the chest oppression and pain of chest-diaphragm qi blockage.
Ming Yi Bie Lu: first defines the medicinal part of the Trichosanthes — mentioning it "governs removing heat, stopping vexation and thirst, and harmonizing the middle" — the "harmonizing the middle" relating to its stomach-channel entry and chest-opening, qi-regulating action.
Xin Xiu Ben Cao: further supplements that Gua Lou Pi can "benefit the throat and stop cough" — matching its heat-phlegm-clearing action.
Ben Cao Gang Mu: discusses the Trichosanthes root (Tian Hua Fen), seed, and peel separately — clearly recording that the peel "moistens lung dryness, lowers fire, treats cough, washes away phlegm stagnation, benefits the throat, stops wasting thirst, and frees the large intestine" — a concrete summary of its heat-phlegm-clearing and chest-opening, qi-regulating actions.
De Pei Ben Cao: mentions that "with Ban Xia it treats phlegm cough; paired with Huang Lian it treats heat phlegm" — pointing out its pairing applications.

2. How Views of Its Nature Changed

Views among physicians differ: the early physicians leaned more to its clearing-draining action — holding it clears and drains the lung heat and frees the chest-diaphragm qi — mostly for the excess patterns of phlegm turbidity blockage. In the Ming and Qing dynasties, with the development of warm-disease theory, some physicians began to value its moistening action — holding it attends to the body fluids while clearing the phlegm, fitting the deficiency-with-excess patterns of dryness-heat harming fluids — extending its scope from the pure excess patterns to the deficiency-with-dryness cases. Some physicians also stress its contraindications — for example, the Ben Cao Jing Shu records "those with spleen-stomach deficiency-cold and unfirm stool should avoid it" — pointing out that its cold nature does not fit those with a weak spleen and stomach, making later physicians pay more attention to pattern differentiation and avoid blind use.

Core Efficacies & Traditional Applications

Traditional Functions

Clears heat and resolves phlegm, moves qi and widens the chest.

1. First Direction: Clearing Heat-Phlegm

Traditional action: clear the heat-phlegm — targeting the phlegm turbidity blockage of lung heat or dryness-heat.
Typical signs: a cough with yellow, sticky phlegm that is hard to cough out, with chest oppression, a dry throat, and a red tongue with a yellow greasy coating — these symptoms are more obvious in autumn dryness or when lung heat is worsened by spicy food.
Usual combinations: often paired with Huang Qin and Huang Lian to strengthen the heat-clearing, or with Xing Ren and Jie Geng to strengthen the lung-diffusing, cough-stopping effect.
Who should not self-use: those with a cold-phlegm cough — thin, white phlegm and fear of cold — should not self-use, because the cold nature of Gua Lou Pi worsens the cold-phlegm congelation and is not good for the phlegm discharge.

2. Second Direction: Regulating Qi and Opening the Chest

Traditional action: regulate the qi and open the chest — targeting the chest oppression and pain of chest-diaphragm qi blockage.
Typical signs: chest oppression like something stuck in the chest, worsened by low mood or after eating, with belching, bloating, and a thin greasy coating — especially the chest-diaphragm qi stagnation of modern people from work pressure and emotional anxiety.
Usual combinations: often paired with Zhi Ke and Chen Pi to strengthen the qi-regulating action, or with Xie Bai to ease the chest-diaphragm pain.
Who should not self-use: those with the chest oppression of qi deficiency — shortness of breath, fatigue, worse after activity — should not self-use, because its qi-regulating action wastes the upright qi and worsens the qi-deficiency symptoms.

3. Classic Pairing: Gua Lou Pi With Zhi Ke

The most common pair is Gua Lou Pi with Zhi Ke: Gua Lou Pi is good at clearing the phlegm turbidity of the chest and lungs while freeing the chest-diaphragm qi; Zhi Ke is good at regulating the qi and opening the middle — freeing the qi stagnation of the spleen, stomach, and chest-diaphragm. Combined, they both strengthen the qi-regulating action and help clear the phlegm turbidity — a mutually coordinating relation, fitting the patterns of chest-diaphragm qi stagnation with phlegm turbidity blockage — such as chest oppression, a cough with sticky phlegm, and bloating. However, this pairing needs the physician's pattern diagnosis — especially those with a weak spleen and stomach, who need dose adjustment or the addition of spleen-stomach-protecting herbs — do not use on your own.

Modern Research

Modern research offers useful context, but Traditional Chinese Medicine prescribes on whole-pattern diagnosis rather than isolated compounds.

1. Main Chemical Constituents

The constituents detected in Gua Lou Pi include flavonoid compounds, triterpenoid saponins, organic acids, polysaccharides, and volatile oils. Among them, the flavonoids — such as rutin and quercetin — are naturally present active substances in the plant; the triterpenoid saponins are constituents characteristic of the Trichosanthes genus and one of its main active constituents. In in vitro experiments, these flavonoid constituents show a certain inhibitory effect on bacteria common in the respiratory tract; in animal experiments, after giving the extract to model animals by gavage, it was observed to help dilute the phlegm and promote the discharge of respiratory mucus; the existing human clinical research is still relatively limited, and no clear clinical efficacy conclusion has been reached.

2. Current Research Directions

Current research on Gua Lou Pi mainly explores the active mechanisms related to its phlegm-transforming and qi-regulating actions:

Regulation of respiratory mucosal secretion — the volatile oil constituents can regulate the secretory function of the respiratory mucosa, helping reduce the viscosity of the phlegm.
Relief of chest-diaphragm spasm — in experiments, the extract can influence the qi-related neurotransmitters in animals, easing the spasm feeling of the chest-diaphragm area and thereby reducing the chest-oppression discomfort.

However, most of these studies are at the animal or in vitro cell level — more well-designed human studies are still needed to verify these results in actual clinical use.

3. Limitations of Current Research

Lab results are not clinical efficacy — the observed actions of in vitro and animal experiments may not be fully replicated in the human body.
Extracts and monomers are not the same as traditional slices — the concentration and dose of the extracts differ greatly from the daily-used slices — cannot be converted directly.
Species, origin, and processing vary between studies — the Trichosanthes varieties, origins, and processing methods differ across studies — the results may differ and cannot be unified.
A single component does not define the whole herb — Gua Lou Pi acts through the joint work of many constituents — a single constituent's activity cannot represent the whole herb's overall action.

Comparing Similar Herbs

1. What They Share

Choosing the similar herb Gua Lou Ren, the two share these points:

Both have the phlegm-transforming action — both help clear the phlegm turbidity of the respiratory tract — fitting the cough-with-phlegm patterns.
Both are used for the chest-lung patterns — both act on the chest-diaphragm and lung, easing the chest oppression and cough discomfort.
Both need the constitution and dose considered — those of a cold constitution or with a weak spleen and stomach need caution with either — do not overuse.

2. The Key Differences: Gua Lou Pi vs. Gua Lou Ren

Nature and flavors: Gua Lou Pi is cold with sweet and slightly bitter flavors — clear-transparent — leaning to dispersing; Gua Lou Ren is also cold with a sweet flavor — moistening — leaning to nourishing.
Focus: Gua Lou Pi is good at clearing heat-phlegm and regulating the qi to open the chest — leaning to freeing the chest-diaphragm qi stagnation and clearing the sticky phlegm turbidity; Gua Lou Ren is good at moistening the lung, transforming phlegm, and moistening the intestines to free the stool — leaning to nourishing the lung dryness and helping the intestines move.
Qi tendency: Gua Lou Pi is "floating" — acting upward and outward — leaning to freeing the qi and scattering the phlegm turbidity; Gua Lou Ren is "descending" — acting downward and inward — leaning to moistening, descending, and freeing the stool.
Best fit: Gua Lou Pi fits the chest oppression, sticky phlegm hard to cough, and chest-diaphragm qi stagnation; Gua Lou Ren fits the cough with dry phlegm, dry stool, and lung dryness.
Not suitable: Gua Lou Pi — not for those with cold phlegm or qi deficiency; Gua Lou Ren — not for those with spleen-stomach deficiency-cold or loose stool.
Use scenes: Gua Lou Pi is more commonly used in the formulas for chest-diaphragm discomfort and cough with sticky phlegm — such as the chest-oppression formula Gua Lou Xie Bai Ban Xia Tang; Gua Lou Ren is more commonly used in the food therapy or formulas for lung-dry cough and dry stool — such as pairing with Xing Ren to moisten the lung.

3. One-Sentence Summary

Simply put, Gua Lou Pi leans toward clearing and scattering the phlegm turbidity and qi stagnation of the chest-diaphragm, whereas Gua Lou Ren leans toward moistening the lung dryness and the intestines. Both can be used for the cough-with-phlegm regulation, but they are not interchangeable.

Classical Formulas Containing Gua Lou Pi

Qing Qi Hua Tan Tang

清氣化痰湯

Formula CategoryPhlegm-Resolving FormulasPrimary PatternPhlegm-HeatPrimary FunctionClear heat, resolve phlegm, regulate QiRelated ConditionsChest Tightness·Excessive Mucus

View Formula Profile Read Complete Guide

Formulas vs. Single Herbs

A formula is many herbs working together — through the lord-minister-assistant-courier pairing, attending to different mechanisms: Gua Lou Xie Bai Ban Xia Tang both transforms phlegm and warms and frees; Qing Qi Hua Tan Wan both clears heat and regulates qi. A single herb cannot simply replicate a full formula's effect. The doses and combinations in a formula are holistic — each herb's amount is designed: the dose of Gua Lou Pi in Gua Lou Xie Bai Ban Xia Tang differs from that in Qing Qi Hua Tan Wan, and the actions differ accordingly. Many readers misunderstand that if a herb works in a formula, taking it alone produces the same effect — in fact, a single herb's action is single, while a formula is the synergy of many herbs — more comprehensive and better fitting complex patterns — so do not build formulas from online articles, especially with a herb of definite nature like Gua Lou Pi.

Diet & Daily Home Use

1. Home Tea

Gua Lou Pi Chen Pi Tea: Gua Lou Pi 3 g, Chen Pi 2 g, a little honey. Rinse the Gua Lou Pi and Chen Pi with clean water, put them in a teapot, steep in boiling water for 10 minutes, then add an appropriate amount of honey to taste. Suited to the mild chest oppression and cough from chest-diaphragm qi stagnation and sticky phlegm — especially the discomfort after low mood or rich food — fitting the daily regulation of modern people. Not for those with a cold-phlegm cough (thin white phlegm and fear of cold) or spleen-stomach deficiency-cold (loose stool and a cold abdomen). Suggested: 2–3 times a week; do not drink long-term continuously.

2. Decoction and Processing Differences

The difference between the raw and the honey-processed Gua Lou Pi is clear: the raw leans to clearing heat-phlegm and regulating the qi to open the chest — fitting the phlegm-heat or qi-stagnation patterns; the honey-processed leans to moistening the lung and transforming phlegm — fitting the cough of lung dryness. For home decoction, Gua Lou Pi needs no special handling — neither pre-boiling nor late addition — decoct it directly with the other herbs; control the decoction time at 15–20 minutes, not too long, to avoid the volatilization of the effective constituents. Different forms cannot be converted directly — the tea uses a small amount of slices while the medicinal decoction dose is larger — do not replace the medicinal dose with the tea dose.

3. Dosage and Course

The common dose in traditional prescriptions is 6–12 g — the medicinal decoction generally uses about 10 g — while the food-therapy tea dose is much smaller, generally 3–5 g, to avoid excess. The food-therapy and medicinal doses differ greatly — do not confuse them; for daily regulation use the tea, and do not decoct the medicinal dose on your own. Long-term continuous use is not advised — even in food therapy, pause after drinking for a period; those of a cold-leaning constitution should especially avoid long-term use. Special groups — such as pregnant women and children — should consult a physician or pharmacist before use; do not self-use.

Contraindications & Safety Warnings

1. Who Should Avoid It

The cold-phlegm cough — thin white phlegm, fear of cold, and a white greasy coating — using Gua Lou Pi may worsen the cold-phlegm congelation.
Spleen-stomach deficiency-cold — loose stool, a cold abdomen, and poor appetite — using Gua Lou Pi may harm the spleen-stomach yang.
Pregnancy and breastfeeding — no clear safety evidence currently — to avoid risk, not advised.
Children and the elderly — special constitutions with low tolerance to herb natures — use after a physician's assessment.
Allergy to Cucurbitaceae plants — those allergic to gourds, loofah, and the like may also be allergic to Gua Lou Pi.
Those in special treatment — such as taking anticoagulant or blood-pressure medications — consult a doctor before use, to avoid interactions.

2. Interactions and Diet Notes

Gua Lou Pi may affect the action of anticoagulant, blood-pressure, glucose-lowering, and sedative drugs: with anticoagulants, it may increase the risk of bleeding; with blood-pressure medications, it may strengthen the lowering effect and cause blood pressure to drop too low. There is no sufficient evidence of a general "food clash" between ordinary foods, but certain herbs can interact with specific drugs — those on medication should consult a doctor or pharmacist first. If use together is needed, it is best to leave an interval of 1–2 hours, to avoid affecting the absorption or metabolism of the drugs.

3. Adverse Reactions and Overdose Risk

Gua Lou Pi has relatively few adverse reactions, but overuse may cause gastrointestinal discomfort — nausea, vomiting, and diarrhea — especially in those with a weak spleen and stomach. If marked discomfort, allergy signs (such as rash or itching), persistent vomiting, breathing difficulty, altered consciousness, or rapidly worsening symptoms appear, stop at once and seek medical care — do not self-handle.

Frequently Asked Questions About Gua Lou Pi

What is Gualoupi? Is it the same as Gualouren or Quangualou?

Gualoupi is the dried mature pericarp of Trichosanthes kirilowii or Trichosanthes rosthornii, Latin name Trichosanthis Pericarpium. It is a common Chinese medicine centered on clearing heat and transforming phlegm, and benefiting qi to expand the chest. Gualouren moistens the intestines and promotes bowel movements. Quangualou clears heat and transforms phlegm while also promoting bowel movements. They cannot be used interchangeably in equal amounts. Prescribe as Gualoupi. Caution in spleen-stomach deficiency cold.

What are the composition and effects of Gualoupi?

Pharmacopoeial name Gualoupi, Latin Trichosanthes kirilowii Maxim. or Trichosanthes rosthornii Harms. Sweet in taste, cold in nature, enters the Lung and Stomach meridians. Functions to clear heat and transform phlegm, and benefit qi to expand the chest. Used for phlegm-heat cough and chest oppression with hypochondriac pain. Clears heat and expands the chest.

How to choose between raw and processed? Can Quangualou replace it?

Pericarp is used raw. Quangualou emphasizes promoting bowel movements rather than strongly expanding the chest, and cannot replace it in equal amounts. Commercial products are standardized; do not adjust arbitrarily.

What is the dosage of Gualoupi? Can it be used daily as a phlegm-transforming tea?

Decoction, 6-10g. Modern use requires physician-determined dosage. It is not a year-round "Gualoupi tea." Spleen-stomach deficiency cold will be further injured by prolonged use. Phlegm-heat cough requires short-term, physician-determined dosage and cannot replace evaluation.

What are the contraindications of Gualoupi? Can pregnant women use it?

Not suitable for spleen-stomach deficiency cold. Should not be used with Chuanwu, Caowu, or Fuzi. Pregnant women require physician evaluation. Stop if loose stools or abdominal pain occur. Seek immediate medical care for severe chest pain or high fever.

Can Gualoupi clear heat, transform phlegm, and expand the chest?

It can assist phlegm-heat cough and chest oppression with hypochondriac pain. It clears heat and transforms phlegm, and benefits qi to expand the chest, but is not a specific remedy for all cough or all chest pain.

Can Gualoupi be taken daily as a phlegm-transforming or chest-expanding tea?

Phlegm-heat cough can be used short-term in formulas; spleen-stomach deficiency cold will be further injured. The idea that "Gualoupi must expand the chest" cannot replace evaluation. Clearing heat and expanding the chest requires physician-determined formulation and dosage.

How to choose between Gualoupi, Quangualou, Gualouren, Xiebai, and Banxia?

Gualoupi clears heat and expands the chest, suited to phlegm-heat chest oppression. Quangualou clears heat and also promotes bowel movements. Gualouren moistens the intestines. Xiebai unblocks yang and dissipates nodules. Banxia dries dampness and transforms phlegm. Choose Gualoupi for expanding the chest; Quangualou for promoting bowel movements; Gualouren for moistening dryness; Xiebai for unblocking yang; Banxia for drying dampness. Pattern differentiation applies, but large doses of Gualoupi are contraindicated in spleen-stomach deficiency cold.

How is Gualoupi commonly modified? What is a representative usage?

Modifications depend on the pattern. Add Xiebai for chest oppression; add Huangqin for phlegm-heat. Specify Gualoupi; do not substitute Quangualou in equal amounts for expanding the chest.

How to select and store Gualoupi?

Choose regular Chinese medicinal materials with intact pericarp. Discard if moldy, damp, or abnormal in odor. Store in a dry place. Purchase "Gualoupi"; do not substitute Quangualou or Gualouren in equal amounts for clearing heat, transforming phlegm, and expanding the chest.

Related Products

Nong's Gua Lou Pi (Snakegourd Peel) Single Herb 5:1 Concentrated Granules $74.23

Hoi Tin Gua Lou Pi (Snakegourd Peel) Single Herb 5:1 Concentrated Granules, 100 g TCM Herbal Supplement

Hoi Tin Gua Lou Pi (Snakegourd Peel) Single Herb 5:1 Concentrated Granules $38.59

Hoi Tin Qing Qi Hua Tan Tang Extract Granules

Hoi Tin Qing Qi Hua Tan Tang (Clear Qi and Transform Phlegm Decoction) 5:1 Concentrated Granules $30.50

Medical Disclaimer — This article is provided for educational purposes only and describes traditional Chinese medicine concepts. It is not medical advice, and it is not intended to diagnose, treat, cure or prevent any disease. Always consult a qualified practitioner before using any herb, particularly if you are pregnant, nursing, taking medication or managing a diagnosed condition.