Meng Chong (tabanus, gadfly)

Chinese Herb Actions

Chinese Herb Dosage

• What is the typical dosage of Meng Chong?

  Our record gives 1–1.5 g in decoction and 0.3 g as powder, per Chen. Both figures are small, and the gap between them is the important part: the powdered dose is roughly a fifth of the decocted dose, because the active proteins and peptides are concentrated in the raw material and are not fully extracted into a water decoction.

  • Decoction: 1–1.5 g — among the lowest decoction ranges anywhere in the materia medica.
  • Powder: 0.3 g — a deliberately much smaller ceiling, which should not be scaled up to the decoction figure.
  • Compare the paired herb. Shui Zhi is recorded here at 3–6 g decocted and 0.3–0.6 g as powder. Meng Chong is dosed lower still on the decoction side, which is the practical expression of it being the harsher of the two.

  This is reference information about how the medicinal is described in the literature, not a prescription. Meng Chong is a slightly toxic, blood-breaking, animal-derived substance and belongs in the hands of a qualified practitioner.

  Source: our own herb records for Meng Chong (Chen ranges as recorded) and for Shui Zhi. Cross-referenced against published materia medica consensus and multiple online sources. Reference only — not a prescription.

Chinese Herb Contraindications & Cautions

• Is Meng Chong safe? Who should not take it?

  Meng Chong is contraindicated in pregnancy, and that is the firmest caution attached to it. Our own record states plainly: do not use during pregnancy. It is a strong blood-breaking medicinal, the whole class is traditionally withheld in pregnancy, and our record also classifies the herb itself as slightly toxic.

  • Pregnancy — contraindicated. Documented in our record and consistent across the materia medica for the blood-breaking category. This is the single most important line on the page.
  • Bleeding tendency, active bleeding, or planned surgery. A blood-breaking medicinal is a poor fit where bleeding is already the problem, and here there is a specific human signal rather than only an inference — see the interactions section on the acute-intracerebral-haemorrhage trials.
  • Deficiency without stasis — traditionally inappropriate; this is an attacking medicinal, not a tonic.
  • Animal-derived (reference note). Meng Chong is not suitable for vegetarians or vegans, and the animal source should be disclosed to anyone taking it.
  • Allergy (reference note). Horsefly salivary glands are a documented source of human allergens, including a platelet-aggregation-inhibiting allergen characterised in 2011. That research concerns bite exposure rather than the oral medicinal, but it makes insect-protein sensitivity a reasonable thing for a practitioner to ask about before dispensing an insect medicinal.
  • Identity and sourcing (reference note). Several gadfly species supply the trade and they are separated microscopically rather than by eye; authenticated material from a reputable supplier is a real quality question for this medicinal.
  • Professional supervision. Slightly toxic, dosed in fractions of a gram, blood-breaking — not a self-prescribing herb.

  Note: our record additionally states that Meng Chong “has been shown to cause teratogenic (birth defects) effects.” We could not locate a resolvable published study demonstrating teratogenicity for this medicinal — the identical wording appears on our Shui Zhi record and was flagged there for the same reason — so we have not repeated that specific claim as sourced fact. The pregnancy contraindication itself is well established and stands on its own. The existing wording is left unchanged and flagged for owner review.

  Sources: our own herb record (pregnancy contraindication, slightly-toxic classification); allergen characterisation from PMID 21848516, DOI 10.1111/j.1398-9995.2011.02683.x (Allergy, 2011 — a novel allergen Tab y 1 with platelet-aggregation-inhibitory activity from horsefly salivary glands); identification from PMID 21046727; human bleeding signal from PMID 31076468, PMC 6528012, DOI 10.1136/bmjopen-2018-024932. Neutral reference notes, not a safety guarantee.

Chinese Herb Toxicity & Overdose

• Our record classifies Meng Chong as slightly toxic, and the reference doses it carries — 1–1.5 g decocted, 0.3 g as powder — are among the smallest in the materia medica, which is the practical expression of that classification. Our record holds no separate overdose description for this herb.

  What can be stated as neutral reference fact:

  • The expected risk profile is bleeding. The characterised chemistry of the animal is anticoagulant and antiplatelet — fibrinogenolytic enzymes, thrombin-inhibitor peptides and platelet-aggregation inhibitors have all been isolated from horsefly tissue. Any adverse effect from excess would be expected to follow that line, and the one relevant human trial programme found exactly that pattern (see interactions).
  • The dose ceiling exists for a reason. A herb dosed at 0.3 g in powder form is being handled as a potent substance, not a mild one.
  • Species variability. Because the medicinal is a genus rather than a single species, potency cannot be assumed uniform across material from different sources.

  Sources: our own herb record (slightly-toxic classification and dose ranges); constituent basis from PMID 19531497, PMC 2742439, DOI 10.1074/mcp.M900186-MCP200 and PMID 16756088, DOI 10.1007/BF02968593 (Archives of Pharmacal Research, 2006 — purification of an anticoagulant protein from Tabanus bivittatus). Reference note only.

• This herb is considered slightly toxic.
  (while some Chinese herbs are toxic, it must be noted that many come prepared, or are combined, to mitigate their toxicity)

Herb-Drug Interactions

• Does Meng Chong interact with blood thinners?

  Caution with anticoagulant and antiplatelet drugs is reasonable, and unusually for a herb of this kind there is a real human safety signal behind it rather than only an inference from chemistry. Our record holds no interaction note of its own, so what follows is drawn from the published literature.

  • The human signal. A randomised, double-blind, placebo-controlled multicentre trial in 324 patients with acute intracerebral haemorrhage compared a blood-stasis-removing formula containing hirudo and tabanus against the same formula without them and against placebo. The arm containing the two animal medicinals showed no clinical benefit and a significantly higher overall rate of treatment-emergent adverse events, including all three serious adverse events; the authors attributed the increased bleeding risk to the blood-stasis-removing herbs. A follow-up trial protocol in the same programme states the earlier finding directly: use of the preparation within six hours of the event may increase the risk of haematoma enlargement and gastrointestinal bleeding. This is the same trial cited on our Shui Zhi record, and it applies to both animals in the pair.
  • The chemistry is consistent with it. Anticoagulant proteins have been purified from horsefly tissue, including a 65 kDa protein from Tabanus bivittatus that prolonged human plasma clotting time and showed potent, specific antithrombin activity in vitro; salivary-gland surveys have added fibrinogenolytic enzymes and platelet-aggregation inhibitors.
  • What is not established. We found no dedicated human pharmacokinetic or pharmacodynamic interaction study of the dried medicinal with warfarin, a direct oral anticoagulant, heparin, aspirin or clopidogrel. Most of the anticoagulant chemistry above was characterised from salivary glands or from whole-insect extracts in the laboratory, which is a different exposure from an oral dose inside a decoction.
  • Practical reading. Anyone on anticoagulant or antiplatelet therapy, or with a bleeding disorder, should have this herb reviewed by their prescriber and a qualified practitioner before use. That is precaution grounded in a real human safety signal — not a proven pharmacokinetic interaction.

  Sources: PMID 31076468, PMC 6528012, DOI 10.1136/bmjopen-2018-024932 (BMJ Open, 2019 — safety and efficacy of herbal medicine for acute intracerebral haemorrhage); PMID 30224926, PMC 6129335, DOI 10.1155/2018/3120179 (2018 — follow-up trial protocol stating the earlier haematoma-enlargement and gastrointestinal-bleeding finding); PMID 16756088, DOI 10.1007/BF02968593; PMID 19531497, PMC 2742439, DOI 10.1074/mcp.M900186-MCP200. Reference information, not clinical advice.

Western / Biomedical Research

Chinese Herb Clinical Studies & Research

Provided as research context — a summary of published biomedical study, not a therapeutic or medical claim.

• Is there modern research on Meng Chong (Tabanus)?

  Yes — a substantial and genuinely interesting molecular literature on horsefly anticoagulants, an animal literature on the leech-and-gadfly pairing, one relevant human trial programme, and no clinical efficacy evidence for the dried medicinal on its own. The research is context, not evidence of benefit.

  • The anti-thrombosis repertoire (the flagship work). A 2009 proteomic and transcriptomic study of 60,000 pairs of salivary glands from the horsefly Tabanus yao identified seven families of antihaemostatic molecules: ten fibrinogenolytic enzymes (the first such family characterised from arthropods), a further fibrinogenolytic enzyme acting on both alpha and beta chains, ten RGD-motif platelet-aggregation inhibitors, five thrombin-inhibitor peptides, three vasodilator peptides, an apyrase and a peroxidase. The authors framed the work explicitly as revealing the molecular basis of a traditional Eastern medicinal insect. An earlier 2008 study on the same species added antimicrobial peptides, a hyaluronidase and immune-suppressant activity to the picture.
  • A named lead compound. Tablysin-15, an RGD-containing disintegrin from Tabanus yao salivary gland, binds platelet and endothelial integrins with high affinity, inhibits platelet aggregation induced by collagen, ADP and convulxin, attenuates thrombus formation under flow, inhibits endothelial tube formation, and showed antithrombotic properties in vivo. It has been discussed as a prototype for developing antithrombotics.
  • Whole-insect chemistry. An anticoagulant protein of 65 kDa was purified from whole Tabanus bivittatus, prolonging human plasma clotting time with specific antithrombin but not anti-factor-Xa activity; a fibrinogenolytic enzyme from horsefly salivary gland was expressed and characterised in 2017.
  • The classical pairing, tested. The 2009 rat blood-stasis study of leech-to-gadfly ratios described in the notes section found the combinations outperformed either animal alone, with the classical 4:3 ratio giving the best anticoagulant effect.
  • Human trial (safety signal, not efficacy). The randomised controlled trial in acute intracerebral haemorrhage described in the interactions section is the only human evidence we could verify that bears directly on this medicinal, and it is a bleeding-risk finding, not a benefit.
  • Identification and quality. Microscopic identification work separates six kinds of gadfly used as the medicinal, and gas-chromatographic analysis of the fatty constituents of Tabanus bivittatus has been published — the beginnings of a quality-control literature rather than a mature one.

  Overall: the mechanistic case for “this animal contains real anticoagulants” is strong and well documented, the animal data on the classical pairing is consistent, and human efficacy evidence for the dried medicinal is absent. The one good human trial is a safety finding, and it points toward bleeding risk rather than benefit.

  Sources: PMID 19531497, PMC 2742439, DOI 10.1074/mcp.M900186-MCP200; PMID 18087067, DOI 10.1074/mcp.M700497-MCP200; PMID 21475772, PMC 3499621, DOI 10.1160/TH11-01-0029 (Thrombosis and Haemostasis, 2011 — Tablysin-15); PMID 16756088, DOI 10.1007/BF02968593; PMID 27138045, DOI 10.1016/j.pep.2016.04.014 (Protein Expression and Purification, 2017 — fibrinogenolytic enzyme from horsefly salivary gland); PMID 12243231 (Medical and Veterinary Entomology, 2002 — anticoagulant activities in salivary glands of tabanid flies); PMID 20034208; PMID 31076468, PMC 6528012, DOI 10.1136/bmjopen-2018-024932; PMID 30224926, PMC 6129335, DOI 10.1155/2018/3120179; PMID 21046727; PMID 23901639 (Journal of Chinese Medicinal Materials, 2013 — fatty constituents of Tabanus bivittatus by GC-MS). Research context, not a therapeutic claim.

Chinese Herb Notes

• Why are Meng Chong and Shui Zhi always used together?

  Because they are the two ends of the same strategy: both are animal medicinals that break blood, and the classical formulas pair them rather than choosing between them. Shui Zhi is the leech; Meng Chong is the horsefly. Both are blood-feeding animals whose medicinal value the tradition connected to that habit long before anyone could name a thrombin inhibitor, and modern work has since found genuine anticoagulant chemistry in both.

  • What the classical pairing looks like. Di Dang Tang is the classical formula in which the two appear together; in our own formula records Meng Chong appears in Da Huang Zhe Chong Wan, the “dry blood” formula, which Shui Zhi also enters.
  • The pairing has been tested. A 2009 Chinese study induced blood-stasis syndrome in rats and compared leech alone, gadfly alone, and four leech-to-gadfly ratios. All three prolonged prothrombin time and activated partial thromboplastin time and inhibited platelet aggregation; the combinations outperformed either animal alone, and the best anticoagulant effect came from the 4:3 leech-to-gadfly ratio — the ratio recommended by the classical monograph. That is an unusually direct experimental hit on a traditional proportion, in an animal model.
  • The chemistry is not identical. The leech line runs through hirudin, a direct thrombin inhibitor. The horsefly line is broader: proteomic surveys of horsefly salivary glands have catalogued fibrinogenolytic enzymes, platelet-aggregation inhibitors, thrombin-inhibitor peptides, vasodilator peptides, an apyrase and a hyaluronidase. They arrive at “moves stuck blood” by different routes.

  Is the dried medicinal the same as a horsefly bite?

  No. The medicinal is a dried, processed insect taken by mouth inside a herbal prescription. The salivary pharmacology described in the research section is what a living female horsefly injects into a host while feeding — and it is also, in the same glands, a documented source of human allergens. The two exposures are not interchangeable, and the salivary-gland literature should not be read as evidence about the dried herb.

  Record flag (identity field left unchanged, raised for owner review): our record’s Chinese-character field for this herb is empty, and its pharmaceutical name is the bare genus Tabanus with no species. Given that published identification work distinguishes six kinds of gadfly in the trade, and that different research groups have worked on different species, the genus-level designation means the pharmacology described here cannot be assumed uniform across every batch. We have not altered the field.

  Sources: our own herb, caution and formula records, and our own record for Shui Zhi; PMID 20034208 (Journal of Chinese Medicinal Materials, 2009 — anticoagulative and antiplatelet aggregation effects of the Hirudo and Tabanus combination in a rat blood-stasis model); PMID 19531497, PMC 2742439, DOI 10.1074/mcp.M900186-MCP200; PMID 18087067, DOI 10.1074/mcp.M700497-MCP200 (Molecular & Cellular Proteomics, 2008 — horsefly salivary gland proteomics with pharmacological testing); PMID 21046727. Reference documentation, not usage guidance.

This herb is considered toxic