Meng Chong
StarTabanus bivittatus Matsumura
Traditionally used for
- Digestion
- Menstrual & women's health
Cautions & contraindications
- Pregnancy
- Bleeding disorders
☯ TCM Properties
Breaks Blood and Dispels Stasis; Transforms and Expels Blood Stasis; Disperses Accumulations and Dissipates Nodules; Promotes Menstruation
Traditional Chinese Uses
Meng Chong (tabanus horsefly) is a toxic Blood-breaking substance used for severe, fixed Blood stasis patterns — including abdominal masses, postpartum retention of placenta, and amenorrhea from Blood clots. Its action is considered more powerful than most plant-based Blood-moving herbs and is used only in small doses, under close supervision, and avoided in pregnancy and in those with bleeding tendencies.
Relationships
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Botanical Description
Meng Chong is the dried body of the female gadfly Tabanus bivittatus Matsumura or related Tabanus species (Tabanidae), large blood-feeding horseflies widespread across East Asia. The insects are caught in summer, killed by exposure to sun or heat, and the wings and legs removed before drying. The body contains proteins, peptides, and anticoagulant substances secreted by the salivary glands to facilitate blood-feeding, including hirudin-like and fibrinolytic factors. In traditional Chinese medicine, Meng Chong is bitter, slightly cold, and toxic, entering the liver channel; it strongly invigorates the blood and breaks up severe blood stasis, used in formulas for amenorrhea, abdominal masses, post-traumatic blood stagnation, and chronic stasis patterns. It is classically paired with Shui Zhi (leech) in the formula Di Dang Tang. Contraindicated in pregnancy and in patients without genuine blood stasis.
Active Constituents
Tabanus anticoagulant protein (TAP)
Protein (direct thrombin inhibitor)Concentration: purified from the whole insect body; 65 kDa, isoelectric point 7.9, no yield per gram of the crude drug reported
The only substance isolated and characterised from this species specifically. It prolonged human plasma clotting time dose-dependently, most markedly the activated partial thromboplastin time, and showed potent specific antithrombin activity in a chromogenic substrate assay with no detectable anti-factor Xa activity. It is activated by copper and zinc ions and is stable at pH 3-6 and 40-70 degrees C. Whether a 65 kDa protein survives decoction and gastric digestion in a way that reaches the circulation has not been tested.
⚠ Drug Interactions
Warfarin, heparins and direct oral anticoagulants (dabigatran, apixaban, rivaroxaban)
The anticoagulant protein purified from whole T. bivittatus bodies is a direct thrombin inhibitor that prolongs human plasma aPTT and thrombin time dose-dependently in vitro. The same class of activity has been found in salivary gland extracts of other tabanids. Meng Chong is also classically paired with Shui Zhi, the leech, in Di Dang Tang and Di Dang Wan, so the exposure in practice is usually to two blood-breaking animal drugs at once. The size of any in vivo effect from an oral dose is unmeasured, which is the reason for a Possible rather than Established rating.
Clinical note: Do not combine with therapeutic anticoagulation outside close monitoring. Stop the herb well before surgery or dental extraction, and ask about it in any unexplained bruising or bleeding on a stable warfarin dose.
Antiplatelet drugs (aspirin, clopidogrel, ticagrelor)
Platelet-directed activity has been characterised in the salivary glands of other horseflies (RGD-containing disintegrins in Tabanus yao) but not in T. bivittatus, and the whole-insect drug has not been tested against platelet function. The caution rests on the drug's thrombin-inhibitory content and its blood-breaking classification, not on a demonstrated antiplatelet effect.
Clinical note: Treat as an additive bleeding risk in practice while recognising the evidence is indirect.
Oxytocin, misoprostol and other uterotonic or abortifacient agents
The classical literature is unambiguous. Ben Cao Jing Shu states that a pregnant woman with abdominal masses and accumulations must not be given Meng Chong, and that anyone with severe qi and blood depletion or wasting of the flesh should avoid it. Ben Cao Gang Mu records the drug as expelling stasis, dispersing masses and freeing menstruation, and notes that physicians of Li Shizhen's day avoided it as toxic although Zhang Zhongjing used it. Modern Chinese sources retain the pregnancy prohibition. The mechanism is presumed to be the same stasis-breaking, menstruation-forcing action for which it is prescribed.
Clinical note: Absolutely contraindicated in pregnancy. Also avoid in patients who are frail, anaemic or blood-deficient, per the classical caution.
Other tabanid species supplied as Meng Chong (Tabanus mandarinus, Tabanus yao, Atylotus species)
The commercial drug 虻虫 is drawn from several tabanid species, and T. bivittatus is treated by some authorities as Atylotus bivittatus. This matters when reading the literature: the widely cited horsefly salivary-gland pharmacology, which includes eleven fibrinogenolytic enzymes, eight RGD disintegrins, four thrombin inhibitors and vasodilator peptides such as vasotab, was worked out in Tabanus yao. The four-species anticoagulant survey often cited alongside it used Hybomitra muehlfeldi, Tabanus autumnalis, Haematopota pluvialis and Heptatoma pellucens. None of that work was done on T. bivittatus.
Clinical note: When a source cites horsefly peptide pharmacology, check which species was used before applying it to the dispensed drug.
Dosage
| Form | Amount | Frequency | Duration | Population | Notes |
|---|---|---|---|---|---|
| not recommended | Not established — see note | Daily | — | — | No ChP monograph. Horsefly (Tabanus). A blood-breaking (破血) agent, strictly contraindicated in pregnancy. Traditionally given in very small amounts in pills and powders rather than by decoction weight; no pharmacopoeial dose is established here. |
Dui Yao — Herb Pairs
The classical two-herb combinations this herb appears in, each with an action neither herb has alone.
The combination of two insect medicinals breaks severe, entrenched blood stasis far more forcefully than plant blood-movers.
Blood amassment in the lower burner with lower abdominal hardness and mania; very harsh, contraindicated in pregnancy and in bleeding or deficiency.
Core pair of a classical formula — Di Dang Tang, Shang Han Lun (Zhang Zhongjing)
Evidence Tier
Moderate evidence · 3 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
3
2 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
Purification and characterization of anticoagulant protein from the Tabanus,Tabanus bivittatus
TAP was isolated from whole T. bivittatus bodies by ammonium sulfate fractionation, Bio-Gel P-60 gel filtration and DEAE Sephadex ion exchange. The purified 65 kDa protein (pI 7.9, internal sequence Ser-Leu-Asn-Asn-Gln-Phe-Ala-Ser-Phe-Ile-Asp-Lys-Val-Arg) prolonged human plasma clotting time, especially aPTT, dose-dependently, and showed potent specific antithrombin activity with no detectable anti-factor Xa activity. This is the only species-specific pharmacology published for the drug.
Identification of Anticoagulant Activities in Salivary Gland Extracts of Four Horsefly Species (Diptera, Tabanidae)
Salivary gland extracts from Hybomitra muehlfeldi, Tabanus autumnalis, Haematopota pluvialis and Heptatoma pellucens all prolonged human plasma clotting time dose-dependently and inhibited thrombin in a chromogenic assay, without inhibiting factor Xa. Partial purification showed species-specific differences in the active fractions. Cited here to show that thrombin inhibition is a family-wide tabanid trait, and to make clear that T. bivittatus was not among the species tested.
Anti-thrombosis Repertoire of Blood-feeding Horsefly Salivary Glands
A proteomic and transcriptomic survey of horsefly salivary glands identifying fibrinogenolytic enzymes, RGD-motif antiplatelet disintegrins, thrombin inhibitors, vasodilator peptides, apyrase and peroxidase. The work was done in Tabanus yao, not T. bivittatus, so it describes the pharmacological potential of the genus rather than the content of the dispensed drug.
⚠ Safety & Contraindications
- Pregnancy
- Bleeding disorders
Contraindications
Its use is prohibited in pregnant women, the weak without blood stasis, or patients with diarrhea.
Source: Xi S, Gong Y. Essentials of Chinese Materia Medica and Medical Formulas. Academic Press/Elsevier, 2017, pp. 252–255.
⚠ Rule-Based Cautions
These entries come from the deterministic rule tables that gate Verscienta's formula tools — classical pair prohibitions, pregnancy and lactation contraindications, and dose ceilings.
Pregnancy
Avoid blood-breaker
Historical Texts
Shen Nong Ben Cao Jing
Han dynastyShang Han Lun
Han dynastyBen Cao Gang Mu
Ming dynasty, 1596Ben Cao Jing Shu
Ming dynasty, 1625References
- Zhang E, Ji X, Ouyang F, Lei Y, Deng S, Rong H, Deng X, Shen H. A minireview of the medicinal and edible insects from the traditional Chinese medicine (TCM) . Frontiers in Pharmacology (2023) [DOI]
- Liu R, Ding Y, Jiang X, Dong R, Zhang Y, Hua Y, Gai C, Wei P. Anticoagulant peptides derived from animal-sourced traditional Chinese medicine and their pharmacological effects . Pharmacological Research - Modern Chinese Medicine (2024) [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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