Lei Wan雷丸
Omphalia · Omphalia Sclerotium · Thunder Ball Fungus
Overview
Lei Wan is the hardened underground sclerotium of a wood-rotting fungus, slightly bitter and cold, graded slightly toxic, and recorded in the classical literature for tapeworm above all, with roundworm, hookworm and childhood parasite-and-food accumulation behind it. Its whole anthelmintic effect rests on a protein-digesting enzyme that is destroyed by heat, which makes the preparation rule absolute: it is never decocted and never heat-processed, only ground and swallowed as a cold powder. It is documented here as classical materia medica — a suspected infestation belongs in a laboratory and then with a prescribing physician.
Nature & Flavor
slightly bitter · Cold · Slightly toxicChannels
Stomach · Large IntestineTypical Dosage
15–21 gActions
3 core actions
- Kills parasites, disperses accumulationThe classical drug for tapeworm, and used secondarily for roundworm and hookworm with abdominal pain; also for the distended abdomen and wasted limbs of childhood attributed to parasite accumulation.
- Destroyed by heat — powder only, never decoctedThe active constituent is a proteolytic enzyme. Boiling inactivates it, and so does hot water in the cup or heat applied during processing — a Lei Wan decoction is inert. Only the raw, finely ground sclerotium taken with cool or lukewarm water carries any action, which is why this herb never appears in a decoction prescription.
- Short courses onlyClassical practice is a course of roughly three days and then reassessment. The slight toxicity and the gastric irritation of a bulk powder both make continuous use inappropriate.
In Formulas
Formulas containing Lei Wan
No published formula lists this herb yet — the library is growing.
Indications & Clinical Uses
- Tapeworm infestation — the classical
- Roundworm and hookworm infestation with abdominal pain
- Childhood: distended abdomen, thin limbs, poor appetite, attributed to parasite accumulation
Each of these is a laboratory diagnosis today, and each is treated with a prescribed antiparasitic.
Western Medical Keywords
Searchable condition terms
Contraindications
Cautions
Slightly toxic. The pharmacopoeia ceiling is 15–21 g per day as powder — 5–7 g per dose, three times daily after food. Do not exceed it, and do not continue beyond a short course without supervision.
Never decocted, never heat-processed. The proteolytic enzyme that carries the entire anthelmintic action is destroyed by heat, so a decoction — or even a hot-water suspension — is pharmacologically empty. Powder, cool water, that is the only usable form.
Not appropriate where the Spleen and Stomach are weak and cold. The powder can provoke nausea, vomiting, abdominal pain and loose stools; stop at the first reaction. Not for prolonged or repeated self-directed use.
Suspected parasitic infection is diagnosed in a laboratory, not from symptoms: a stool ova-and-parasite examination — with serology or imaging where the organism calls for it — identifies what is actually present, and treatment is a modern antiparasitic prescribed by a physician. This entry records the classical materia medica and is not a treatment recommendation.
Contraindicated in pregnancy: Avoid in pregnancy. Lei Wan is graded slightly toxic and is given as a bulk anthelmintic powder — neither is acceptable in pregnancy, and it should also be avoided while breastfeeding. Parasitic infection during pregnancy is managed by the obstetric team, which will choose an agent safe for that trimester.
For licensed practitioners’ reference only
References
- Shen Nong Ben Cao Jing《神农本草经》(classical source, public domain).
2. Bensky, Clavey & Stöger. Chinese Herbal Medicine: Materia Medica, 3rd ed.
3. 《中华人民共和国药典》(2020年版一部).
Professional reference notice. Entries are scholarly references for licensed TCM practitioners and students — not medical advice, and not a recommendation to self-prescribe. Chinese herbal formulas should be used under the guidance of a qualified practitioner. Content is an original editorial compilation by Cura x Cura, cross-checked against the cited references.