Wu Yi (Stinking Elm, paste from the fruit)

Chinese Herb Actions

Chinese Herb Dosage

• What is the typical dosage of Wu Yi?

  Roughly 3–9 g in decoction (some sources give up to ~10 g), or about 2–3 g as a powder. It can be taken alone as a powder for acute roundworm symptoms, or combined into pediatric anti-parasitic formulas such as Bu Dai Wan. Traditional sources caution against prolonged use, consistent with its role as a short-course parasite-expelling herb rather than a tonic.

  Source: standard materia medica dosage ranges; multiple online sources. Reference only — not a prescription.

Chinese Herb Contraindications & Cautions

• Are there cautions for Wu Yi?

  Wu Yi is traditionally reserved for parasite-related excess conditions and is not recommended for long-term use or for patients with weak digestion. Standard materia medica sources describe it as unsuitable for Spleen/Stomach deficiency (weak digestion, poor appetite not caused by parasites) and caution against use in Dry-Heat patterns affecting the Spleen and Stomach. Because it is intended for short-course parasite expulsion rather than tonification, prolonged administration is discouraged.

  • Professional supervision (reference note) — as with other parasite-expelling herbs, use in children and during pregnancy is traditionally reserved for a qualified TCM practitioner’s guidance.

  Source: multiple online sources; general materia medica cautions for the Herbs that Expel Parasites category. Reference note, not usage instructions.

Chinese Herb Toxicity & Overdose

• Low, based on traditional classification. Wu Yi is not listed among the classically “toxic” (yöu dú) herbs in the materia medica sources reviewed, and no significant modern toxicological data specific to this fermented fruit preparation were identified in the literature searched. As with other herbs in the parasite-expelling category, it is intended for short-term use at standard doses rather than prolonged self-administration.

  Source: materia medica category classification (Herbs that Expel Parasites); no dedicated toxicology studies on Wu Yi were located in this search. Reference note, not a safety guarantee.

Herb-Drug Interactions

• No well-established clinical herb–drug interactions specific to Wu Yi are documented in the sources reviewed. No pharmacokinetic or interaction studies on this fermented fruit preparation were located; this reflects an absence of data rather than confirmed safety. (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 Wu Yi (Ulmus macrocarpa)?

  Direct pharmacological research on the traditional fermented fruit preparation itself is very limited. Most modern studies use extracts of Ulmus macrocarpa Hance (typically stem or root bark, not the fermented fruit paste), so they offer species-level context rather than direct evidence for the traditional parasite-expelling use.

  • Immune function (human RCT) — a randomized, double-blind, placebo-controlled trial in healthy adults (500 mg/day extract for 4 weeks) found a short-term (1-week) rise in Th1-related cytokine markers (TNF-α, IL-2) versus placebo, with no significant difference remaining at 4 weeks; the authors concluded a longer-term effect was not established.
  • Gut microbiota (human RCT) — a randomized, placebo-controlled trial in healthy adults (500 mg/day extract for 4 weeks, 16S rRNA fecal profiling) found no significant change in overall microbial diversity, but an increase in specific taxa (Eubacterium ventriosum, Blautia faecis, Ruminococcus gnavus) versus placebo; the response was described as highly individualized.
  • Bone/osteoclast (preclinical) — flavonoid glycosides isolated from U. macrocarpa, including taxifolin-glucoside derivatives, inhibited osteoclast differentiation in mouse bone-marrow-derived macrophages via downregulation of NFATc1; a cell/animal-model finding proposed as a lead for osteoporosis research, not clinical evidence.

  Note: No modern clinical or pharmacological studies confirming the traditional anthelmintic (parasite-expelling) action of Wu Yi specifically were located in this search. The RCTs and preclinical work above studied Ulmus macrocarpa Hance extracts (species-level, mostly bark), not the fermented-fruit Wu Yi preparation used in TCM practice — included here as botanical/species context only. The traditional parasite-expelling use rests on materia medica sources, not on the modern studies cited.

  Sources: PMID 29681977, DOI 10.1155/2018/5690816 (immune function RCT); PMID 34697783, DOI 10.1007/s12275-021-1329-8 (gut microbiota RCT); PMID 35187304 (osteoclast/flavonoid glycoside study, ACS Omega). Research context on the plant species, not a therapeutic claim.

Chinese Herb Notes

• How is Wu Yi prepared, and what does it combine with?

  Wu Yi is not the raw elm fruit itself but a processed, fermented preparation — the ripe fruit (samara) of Ulmus macrocarpa is ground, combined with auxiliary materials (traditionally including elm bark), and fermented and dried into a paste or cake, which is then cut into pieces for use. This fermentation produces the strong odor behind the common name “stinking elm.” Its pharmaceutical name, Praeparatio Fructus Ulmi Macrocarpi, reflects that it is a prepared (processed) medicinal rather than a simple dried fruit.

  Key combination: in the classical pediatric formula Bu Dai Wan (“Cloth Sack Pill”), Wu Yi is one of two chief (king) herbs alongside Shi Jun Zi (Quisqualis Fruit) — Wu Yi’s acrid, dispersing quality is described as complementing Shi Jun Zi’s sweet, tonifying character, killing parasites without chilling the digestive Middle Burner. Other materia medica sources describe it combined with Bing Lang (Areca Seed) and Chuan Lian Zi (Toosendan Fruit) for general parasite expulsion. (Traditional formula context, not treatment advice.)

  Source: multiple online sources, Bu Dai Wan formula monograph; general processing descriptions of Ulmi Macrocarpae Fructus Praeparatus (patent/botanical literature).