Lei Wan (Fruiting Body of Omphalia)

Chinese Herb Actions

Chinese Herb Dosage

• What is the dosage of Lei Wan, and why must it never be decocted?

  Lei Wan is taken only as a raw, unheated powder — never boiled in a decoction. Its antiparasitic action depends on heat-sensitive protease enzymes that denature at boiling-decoction temperatures, so cooking destroys the herb’s effect. Materia medica sources give a general range of about 6–9 g (up to ~15 g) of powder or pills; the specific traditional tapeworm protocol is 5–7 g per dose in warm water, three times daily for three consecutive days (roughly 15–21 g/day total).

  • Never decoct — a 2024 pharmacology review identified two active proteases (a ~16.8 kDa thiol protease and a ~4 kDa metalloprotease subunit) with activity optimal near 37–50°C; several materia medica sources independently cite the enzyme losing activity around 60°C — far below a decoction’s boiling point — which is the practical reason the herb is always taken raw.
  • Form — finely ground/crushed powder, swallowed directly with warm water or taken in pill form; not simmered with the rest of a formula.

  Source: multiple online sources; enzyme kinetics from PMID 39456798 / PMC 11507145 (2024 review). Reference only — not a prescription.

Chinese Herb Contraindications & Cautions

• Are there cautions for Lei Wan?

  Lei Wan is classified as slightly toxic and is traditionally reserved for professional/supervised use, in part because effective antiparasitic dosing sits close to its toxic threshold. Materia medica sources consistently advise caution in patients with Spleen-Stomach deficiency-cold, and some list it as contraindicated in pregnancy.

  • Spleen-Stomach deficiency-cold — use with caution even when parasite accumulation is present, per traditional sources.
  • Pregnancy — traditionally avoided; cited as contraindicated by at least one modern materia medica summary.
  • Classical incompatibility — the Ben Cao Jing Ji Zhu records that Xu Duan (Dipsacus) “detests” Lei Wan; concurrent use is traditionally avoided (a historical pharmacy convention, not a demonstrated pharmacological interaction).
  • Professional dosing — because its action depends on an enzyme destroyed by heat, correct preparation (raw powder only) and dosing are a professional-supervision decision, not a self-dosing guideline.

  Source: multiple online sources. Reference facts, not usage instructions.

Chinese Herb Toxicity & Overdose

• Slightly toxic. Lei Wan’s this site’s own properties record and every cross-checked materia medica source classify it as bitter, cold, and slightly toxic — the toxic designation is a core part of its traditional profile, alongside a narrow effective-dose window for tapeworm treatment. A 2024 pharmacology review characterizes the fungus’s isolated protein/protease fractions as showing a “low toxicity and favorable safety profile” in the preclinical research it surveyed, and separate cell-based studies found its antitumor protein fraction caused little to no toxicity to normal (non-cancerous) gastric cells compared with tumor cells from the same tissue.

  No published overdose case reports, LD50 figures, or a defined toxic dose were located in the sources checked; this is an evidence gap, not a safety guarantee.

  Note: This site’s toxic/endangered flag is currently unset for this herb, while the properties field itself and materia medica consensus classify Lei Wan as slightly toxic. Flagged for owner review; not corrected here since this task only writes content fields.

  Source: cross-checked materia medica toxicity classification; PMID 39456798 / PMC 11507145 (2024 review); PMID 29541181, PMID 28693202 (preclinical normal-vs-tumor gastric cell comparisons). Reference note, not a safety guarantee.

• 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

• No well-established clinical herb–drug interaction studies were found. Given Lei Wan’s slightly toxic classification and its narrow, enzyme-dependent effective dose, practitioner awareness is reasonable for patients on other medications with GI or hepatic burden, or anyone with pre-existing GI compromise; this is a precautionary inference from its toxicity classification, not a demonstrated clinical interaction. (Flagged for practitioner confirmation.)

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 Lei Wan (Omphalia lapidescens)?

  Yes — a 2024 comprehensive review plus a body of preclinical (enzyme/cell/animal-level) pharmacology studies support its traditional antiparasitic use and give preliminary antitumor findings, though human clinical trial evidence is limited. Modern research has also resolved a long-standing taxonomic question about what “Lei Wan” actually is.

  • Two heat-sensitive proteases identified — a 2024 review (PMID 39456798) reports a ~16.8 kDa thiol protease (optimal activity ~37°C, pH 7.48) and a ~4 kDa metalloprotease subunit (optimal ~50°C, pH 7.5) as the fungus’s active antiparasitic components — laboratory enzyme characterization consistent with the traditional rule against decocting the herb.
  • Antiparasitic efficacy, preclinical — the same review reports Omphalia lapidescens preparations performing better than albendazole and comparably to praziquantel against tapeworm, Ascaris (roundworm), Spirometra, and Giardia in the studies it surveyed; a separate study (PMID 26080526) examined effects on Spirometra erinacei plerocercoid infectivity and ultrastructure. Laboratory/animal research, not human clinical trials.
  • Antitumor protein fractions, preclinical — purified Omphalia lapidescens protein fractions suppressed migration, arrested the cell cycle, and induced apoptosis in SGC-7901 (PMID 29541181) and MC-4 (PMID 28693202) gastric cancer cell lines, while showing little to no effect on normal gastric cells in the same studies; cell-culture evidence, not clinical proof.
  • Taxonomy resolved as multi-origin — a 2025 mycological study (PMID 41356275) found commercial “Lei Wan” is not one species but a complex of at least three fungi (mainly Gerronema brunneosquamulosum, of which the older “Omphalia lapidescens”/“Gerronema lapidescens” names are now treated as synonyms), explaining historical naming confusion in the materia medica literature.

  All cited pharmacology and antitumor work is preclinical (enzyme/cell/animal-level); no human clinical trials of Lei Wan itself were located in the sources checked.

  Sources: PMID 39456798, PMC 11507145 (2024 review — proteases, antiparasitic/antitumor pharmacology); PMID 26080526 (Spirometra erinacei plerocercoid study); PMID 29541181 (SGC-7901 gastric cancer cells); PMID 28693202 (MC-4 gastric cancer cells); PMID 41356275 (2025 taxonomy/multi-origin study). Research context, not a therapeutic claim.

Chinese Herb Notes

• Is “Lei Wan” always the same fungus, and how does it differ from other anthelmintic herbs?

  Commercial Lei Wan is a multi-origin sclerotium, not one stable species. It was long known by the Latin name Omphalia lapidescens, later reclassified as Laccocephalum mylittae; a 2025 mycological survey found that market Lei Wan actually comes from at least three related fungi in the genus Gerronema (chiefly Gerronema brunneosquamulosum, of which the older name “Gerronema lapidescens” is now treated as a synonym), plus a separate species, Moniliophthora sclerotium.

  Among the herbs that expel parasites, Lei Wan is distinguished by its tapeworm specialty and its powder-only preparation. Bing Lang (areca seed) and Shi Jun Zi (Quisqualis) are more broadly used for roundworm and general deworming and are prepared normally (decocted or as seed), while Guan Zhong (Dryopteris root) is additionally valued for heat-toxin/epidemic prevention and, charred, for stopping bleeding.

  Traditional formula context: Lei Wan is traditionally combined with Bing Lang, Qian Niu Zi (morning glory seed), and Ku Lian Pi (Melia bark) in classical antiparasitic formulas such as Zhui Chong Wan. (Formula-composition/traditional-use context, not treatment advice.)

  Note: This site’s own record records the Latin as “Scierotium Omphaliae Lapidescentis” (the historical Omphalia lapidescens naming). Current mycological research (PMID 41356275) treats “Omphalia lapidescens” as an outdated synonym and resolves commercial Lei Wan into the Gerronema/Moniliophthora species above. We believe these all refer to the same traditionally-used sclerotium; the identity field is left unchanged pending owner review.

  Source: PMID 41356275 (mycological multi-origin/taxonomy study); multiple online sources.

This herb is considered toxic