Wu Yi芜荑
Ulmi Macrocarpae Fructus Praeparatus · Prepared Large-Fruited Elm Fruit
Overview
Wu Yi is not a raw drug but a preparation: the fruit of the large-fruited elm is fermented and pressed into cakes, which is where its penetrating, rancid smell comes from. Acrid, bitter and warm, it kills parasites and disperses accumulation, and unlike the cold vermifuges it suits a cold, damp Spleen — which is why it appears in childhood prescriptions alongside a digestive. It is also applied externally, as powder, to scabies and ringworm. Recorded here as classical materia medica: the diagnosis is a laboratory one and the treatment a prescribed antiparasitic.
Nature & Flavor
Acrid, bitter · WarmChannels
Spleen · StomachTypical Dosage
3–10 g in decoctionActions
4 core actions
- Kills parasites, disperses accumulationRoundworm and pinworm, and the childhood the tradition attributed to worms plus food stagnation — distended abdomen, thin limbs, irregular appetite. Classically combined with Bing Lang 槟榔 and a digestive herb.
- Dries damp, checks dysenteric diarrhoeaIts acrid warmth dries a cold-damp Spleen, so it fits the case where the vermifuges that are cold in nature would worsen the diarrhoea rather than settle it.
- Applied externally for scabies and ringwormGround and mixed into an ointment or paste for scabies, tinea and stubborn sores. Its parasiticidal reputation on the skin is older and better attested than its internal one.
- A fermented preparationThe medicinal article is the fermented, pressed cake, not the fresh fruit; the smell is diagnostic of the drug and also the reason patients dislike it. Pills or powders are usually easier to take than a decoction.
In Formulas
Formulas containing Wu Yi
Indications & Clinical Uses
- Roundworm and pinworm infestation with abdominal pain
- Childhood with parasite and food accumulation
- Cold-damp diarrhoea accompanying the above
- External: scabies, tinea, stubborn sores
The internal indications need laboratory confirmation and a prescribed antiparasitic.
Western Medical Keywords
Searchable condition terms
Contraindications
Cautions
Not graded toxic in the standard modern texts, though some older records attach a slight toxicity to it — treat it as a herb with a narrow comfort margin rather than a benign one. Ceiling: 10 g per day in decoction, 2–3 g per dose in pills or powders. This figure comes from the textbook and 《中华本草》, since Wu Yi is not a item; confirm against whichever standard your supplier works to.
The taste and smell readily cause nausea and vomiting, which limits the dose more often than toxicity does. Not for a weak Spleen and Stomach with poor appetite, and not for yin deficiency with heat, given its drying warmth.
Externally, do not apply to broken or weeping skin over a large area.
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. Wu Yi is warm, drying and dispersing, and it is used as a vermifuge in children and adults rather than in pregnancy; there is no established safety record for it during gestation, so it should not be taken, internally or in quantity on the skin, while pregnant or breastfeeding.
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. 《中华本草》(State Administration of TCM, modern reference compendium).
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.