Traditionally used for
- Nose & throat
- Cough & breathing
- Digestion
- Urinary & fluids
- Liver & jaundice
Cautions & contraindications
- Heart conditions
- Liver conditions
- Toxic — professional use only
☯ TCM Properties
Induces Vomiting to Expel Phlegm; Clears Damp-Heat and Resolves Jaundice; Drains Water and Reduces Edema
Traditional Chinese Uses
Gua Di (muskmelon pedicle) is a potent emetic substance — one of the few herbs in Chinese medicine used specifically to induce vomiting. It is applied in acute situations where phlegm, toxic substances, or undigested food in the upper digestive tract need to be forcefully expelled. It is also used as a nasal insufflation powder for jaundice treatment. Due to its toxic nature and extreme action, it is reserved for emergency acute situations under strict professional supervision.
Relationships
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Botanical Description
Cucumis melo L. (Cucurbitaceae), the melon or muskmelon, is an annual trailing or climbing herbaceous vine native to Africa and southwestern Asia and widely cultivated worldwide, with hairy stems, palmately lobed leaves, and yellow flowers producing the familiar round to oblong edible fruit. The medicinal Gua Di is the small dried pedicel (the short stem segment attaching each fruit to the vine), collected when the fruit ripens in summer. It is brown, slightly curved, 1-2 cm long, with a flared end where it joined the fruit. The pedicel contains the bitter cucurbitacins (cucurbitacin B, E, and others), highly bioactive tetracyclic triterpenes that act as powerful emetics. In traditional Chinese medicine, Gua Di is bitter, cold, and toxic, entering the stomach channel; it induces vomiting to expel phlegm and undigested food from the upper digestive tract, used in carefully controlled doses for phlegm obstruction of the chest, food stagnation in the stomach, and certain epileptic or maniacal patterns from phlegm. It is used very cautiously due to its strong emetic action.
Active Constituents
Cucurbitacin B
Cucurbitane-type triterpenoidConcentration: the melon pedicel (Pedicellus Meloni) is the principal commercial source of cucurbitacin B; the pedicel concentrates cucurbitacins that are largely absent from the edible fruit flesh
Cucurbitacin B is the main active and the main toxic principle of this drug, and is intensely bitter. It is a potent emetic, which is the classical action of Gua Di, and it also has hepatoprotective, anti-inflammatory and cytotoxic activity, acting in part through inhibition of JAK/STAT3 signalling. Cucurbitacins have a narrow margin between the emetic dose and frank poisoning: overdose produces bloody diarrhoea, uncontrollable vomiting, fever and dehydration, and there is no specific antidote.
Cucurbitacin E (elaterin)
Cucurbitane-type triterpenoidA companion cucurbitacin of the pedicel, likewise bitter, emetic and cytotoxic, and one of the three triterpenoids measured in pharmacokinetic work on cucurbitacin tablets.
Cucurbitacin D
Cucurbitane-type triterpenoidThe third of the major cucurbitacins quantified in Pedicellus Meloni preparations. Like B and E it contributes to both the therapeutic and the toxic profile of the drug.
Cucurbitacin B 2-O-glucoside
Triterpenoid glycosideThe glycosylated form present in the plant material; hydrolysis liberates the aglycone, so the effective cucurbitacin exposure from crude material depends on processing and on gut hydrolysis.
Phytosterols including alpha-spinasterol
SterolMinor sterol constituents of the plant material, not contributing meaningfully to the emetic or toxic action.
⚠ Drug Interactions
Digoxin and other cardiac glycosides
Gua Di is used deliberately to induce forceful vomiting, and severe or repeated emesis causes loss of gastric acid, potassium and volume. The resulting hypokalaemia and metabolic alkalosis potentiate cardiac glycoside binding to the Na+/K+ ATPase, so a digitalised patient can become toxic without any change in dose.
Clinical note: Do not use an emetic herb in a patient on a cardiac glycoside. If emesis has occurred, check potassium and consider a digoxin level.
All orally administered medicines
The therapeutic purpose of this drug is to empty the stomach. Any oral medication taken within its window of action will be expelled rather than absorbed. This matters most for anticonvulsants, antiretrovirals, immunosuppressants and oral anticoagulants, where a missed dose has consequences.
Clinical note: Assume oral medication taken near the time of dosing has not been absorbed and reschedule critical drugs. Never use an emetic to treat poisoning by a corrosive substance or a hydrocarbon, and note that induced emesis has been abandoned in modern poisoning practice.
Antihypertensive drugs
Cucurbitacins extracted from Cucumis melo have a demonstrated hypotensive effect in animal work through regulation of vascular tone, and vomiting causes volume depletion on top of that. In a patient already on antihypertensive therapy the two combine to produce hypotension.
Clinical note: Avoid in patients on antihypertensives or with any tendency to postural hypotension; monitor blood pressure if it has been used.
Hepatotoxic drugs and existing liver disease
Cucurbitacin tablets derived from this pedicel have been used in China since the 1970s-80s as adjuvant therapy for chronic hepatitis and primary liver cancer, and reported clinical response rates are reasonable. That therapeutic use should not be confused with safety of the crude drug: cucurbitacins are cytotoxic triterpenoids with a narrow margin, and the doses used in the standardised tablet are far below what crude pedicel powder can deliver.
Clinical note: Do not substitute crude Gua Di for a standardised cucurbitacin preparation in liver disease. If a patient is on a standardised cucurbitacin product, treat the crude herb as a duplicate dose.
Antiemetics (ondansetron, metoclopramide, prochlorperazine)
An antiemetic will oppose the intended emetic action, prompting redosing and risking cumulative cucurbitacin exposure; conversely, if an antiemetic is given after an excessive dose, it may suppress the vomiting without reducing the cucurbitacin already absorbed, masking the severity of poisoning.
Clinical note: Do not use antiemetics to titrate an emetic herb. Excessive vomiting after Gua Di is managed with supportive care and electrolyte correction, and warrants medical assessment.
Dui Yao — Herb Pairs
The classical two-herb combinations this herb appears in, each with an action neither herb has alone.
Bitter emetic action combined with the sour-sweet bean, which together induce vomiting to expel phlegm or food lodged in the chest and upper stomach.
Phlegm or undigested food obstructing the chest in robust patients. Gua Di is toxic; discontinue once vomiting occurs; contraindicated in weak patients, the elderly and pregnancy.
Core pair of a classical formula — Gua Di San, Shang Han Lun (Zhang Zhongjing)
Evidence Tier
Limited evidence · 2 studiesRecorded studies by study design, strongest design at the top. This is a study-design tier only, not a GRADE rating: it does not weigh risk of bias, consistency or precision.
Systematic review / meta-analysis
0
Randomized controlled trial
0
Other clinical trial
0
Observational / case report
0
In vitro / animal
2
1 verified · 1 unverified
Other / unclassified
0
Verified: design read from PubMed for a DOI that resolves to the cited paper Unverified: taken from the study's recorded description
Clinical Studies
Cucurbitacins extracted from Cucumis melo L. (CuEC) exert a hypotensive effect via regulating vascular tone
Cucurbitacins extracted from Cucumis melo lowered blood pressure in an animal model, with the effect traced to regulation of vascular tone rather than to a diuretic or central action. Relevant clinically as the basis for expecting additive hypotension when this drug is used in a patient on antihypertensive therapy.
Comparison of the pharmacokinetic profiles of three triterpenoids after oral administration of a cucurbitacin tablet and nanosuspension by UHPLC-MS/MS
Measured plasma cucurbitacin B, D and E in Sprague-Dawley rats after oral dosing of a cucurbitacin tablet made from Pedicellus Meloni against a nanosuspension of the same material. The nanosuspension reached maximum plasma concentration within two hours and gave significantly higher Cmax and AUC. The practical point for a practitioner is that formulation substantially changes cucurbitacin exposure from the same herb, so dose equivalence between crude pedicel and manufactured products cannot be assumed.
Historical Texts
Shen Nong Ben Cao Jing
Han dynastyShang Han Lun
Han dynastyReferences
- Dai S, Wang C, Zhao X, Ma C, Fu K, Liu Y, Peng C, Li Y. Cucurbitacin B: A review of its pharmacology, toxicity, and pharmacokinetics . Pharmacological Research (2023) [DOI]
- El-Sayed HM, Mahrous EA, Rasheed DM, Abdel-Sattar E. Genus Cucumis: Traditional uses, phytochemistry, pharmacology, clinical application, and toxicology . Chinese Herbal Medicines (2026) [DOI]
This information is for educational purposes only and is not intended to replace professional medical advice. Always consult a qualified healthcare provider before using any herbal remedy, especially if you are pregnant, nursing, or taking medications.
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