Fei Zi (Torreya Seeds)

Chinese Herb Actions

Chinese Herb Dosage

• What is the typical dosage of Fei Zi?

  Roughly 9–15 g in decoction for general use, rising to 30–50 g (or about 30–40 dry-fried/roasted seeds chewed on an empty stomach) when used specifically as a vermifuge. Because Fei Zi is genuinely food-like, it does not require the purging follow-through some anthelmintics do — it can simply be eaten as a roasted snack until parasites/eggs clear.

  • Decoction (general use): about 9–15 g, crushed or cracked before decocting.
  • Antiparasitic use: about 30–50 g in decoction, or 30–40 seeds dry-fried until fragrant and then chewed and swallowed on an empty stomach, typically before meals; traditionally continued daily until stool is clear of parasites/eggs. Hookworm treatment is the indication most specifically associated with this higher dose in the sources reviewed.
  • Preparation: seeds are usually dry-fried (stir-baked) before eating whole/chewed; for decoction they are cracked or crushed to expose the kernel.

  Source: materia medica entries cross-referenced against multiple online sources; consistent with standard materia medica dosing conventions. Reference only — not a prescription.

Chinese Herb Contraindications & Cautions

• Are there cautions for Fei Zi?

  Fei Zi is one of the gentlest anti-parasitic herbs and does not require purging, but its moistening, laxative-leaning nature is not for everyone. It should be used cautiously or avoided with loose stools or Spleen-deficiency diarrhea, and consistent with the mild-laxative action described above, large amounts can over-lubricate the intestines and loosen stool further — a dose-related effect rather than true toxicity.

  • Loose stools / Spleen deficiency with diarrhea — avoid or use cautiously; the moistening action can worsen existing loose stool.
  • Cough due to Lung/Phlegm-heat — two independent materia medica references list this as a contraindication, distinct from the Lung-dryness dry cough Fei Zi is meant to treat.
  • Large doses — can over-lubricate the intestines and loosen stool; keep to the ranges in Dosage and reduce if stool becomes loose.
  • Traditional food-herb incompatibility — multiple online sources note a traditional caution against combining Fei Zi with mung beans.

  Note: multiple online sources also flag caution or contraindication in pregnancy, though the reasoning given (uterine-contracting properties of a related species) is inferential rather than direct evidence on Fei Zi itself. Given two independent sources and the general TCM convention of caution with anti-parasitic/moving herbs in pregnancy, it is kept here as a caution rather than omitted, but should be read as a general professional-supervision note rather than a documented adverse effect.

  Source: multiple online sources (loose stool / Lung-heat cough contraindications independently corroborated); multiple online sources (mung bean and pregnancy notes). Neutral safety reference, not a substitute for professional guidance.

Chinese Herb Toxicity & Overdose

• Low. Fei Zi (Semen Torreyae) is classified as non-toxic in classical materia medica and the Chinese Pharmacopoeia, and Torreya grandis seeds have a long parallel history as an edible nut (a regional food crop, particularly in Zhejiang province) as well as a medicinal. This site’s own record does not flag this herb as toxic or endangered. No significant acute toxicity was reported in the sources reviewed at traditional doses; the main dose-related effect documented is gastrointestinal — loosening of stool with excess intake (see Cautions) — rather than systemic toxicity.

  Source: materia medica consensus (non-toxic classification); this site’s own identity record fields. Reference note, not a safety guarantee.

Herb-Drug Interactions

• No established clinical herb–drug interactions are documented in the sources reviewed. A 2018 mechanism study identified two anthelmintic compounds in Semen Torreyae (galangal acetate and miogadial) that do not appear to act through the targets of conventional anthelmintic drugs (ivermectin, levamisole, benzimidazoles, aldicarb) or through TRP channels (see Research) — suggesting the herb’s traditional vermifuge action works by a distinct mechanism from pharmaceutical dewormers, though this has not been studied as a formal drug-interaction question. No data on interaction with laxatives or other GI medications was found.

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 Fei Zi (Semen Torreyae)?

  Yes — research on Torreya grandis seed is concentrated in identifying genuinely anthelmintic active compounds and characterizing its nutrient/lipid profile, both largely preclinical; no human clinical trial specific to Fei Zi’s traditional antiparasitic, laxative, or antitussive use was found in the sources reviewed.

  • Anthelmintic mechanism (2018, preclinical) — bioassay-guided isolation using a Caenorhabditis elegans (nematode) model identified two active compounds from Semen Torreyae, galangal acetate (IC50 58.5±8.9 µM) and miogadial (IC50 25.1±5.4 µM), which acted synergistically and remained effective against drug-resistant nematode strains. Neither compound appeared to act via TRP channels or the targets of currently used anthelmintic drugs, indicating a genuinely novel mechanism. This gives the traditional vermifuge use real, if preclinical (nematode-model, not human), pharmacological grounding.
  • Cited in an anthelmintic drug-discovery review (2020) — a review of plant-based candidates for novel anthelmintic development cites this Semen Torreyae finding as a notable example of a natural product acting outside existing anthelmintic drug classes; review-level, not new data.
  • Nutrient / functional-compound composition (2024, preclinical) — a comprehensive review of Torreya grandis nuts and processing byproducts describes the seed as rich in oil, protein, tocopherols, phytosterols, and phenolics, including the unusual fatty acid sciadonic acid; preclinical (cell/animal) studies associate sciadonic acid with lipid-lowering and metabolic effects. This research reflects the seed’s food/nutrition profile rather than its traditional anthelmintic, laxative, or antitussive actions, and the review notes human clinical validation remains limited.

  Overall: the traditional vermifuge use has supporting preclinical mechanism data; human clinical evidence specific to Fei Zi was not found in the sources reviewed.

  Sources: PMID 29933012, DOI 10.1016/j.jep.2018.06.026 (bioassay-guided anthelmintic compound isolation, Journal of Ethnopharmacology, 2018); PMID 32182910, DOI 10.3390/biom10030426 (plant-based anthelmintics review, Biomolecules, 2020); PMID 39593315, DOI 10.1016/j.foodres.2024.115232 (functional-compound review, Food Research International, 2024). Research context, not a therapeutic claim.

Chinese Herb Notes

• How is Fei Zi different from Shi Jun Zi, Bing Lang, and Ku Lian Gen Pi, and what is it combined with?

  All four are used against intestinal parasites, but Fei Zi is the mildest and most food-like of the group, and the only one that also moistens the intestines and the Lung as built-in secondary actions. Where the others rely on bitterness or forceful purging, Fei Zi’s sweet, oily nature lets it be eaten like a snack while it works.

  • Shi Jun Zi — sweet, warm; especially targets roundworm and pinworm and uniquely strengthens the Spleen, making it the classic pediatric choice; often paired with Fei Zi for broader parasite coverage.
  • Bing Lang (Betel Nut) — bitter, pungent, warm; more forceful, moves qi and purges downward, broad-spectrum including tapeworm; combined with Fei Zi and Nan Gua Zi for tapeworm, and with Guan Zhong for hookworm.
  • Ku Lian Gen Pi (China Tree Root Bark) — bitter and more toxic/harsher on digestion; generally regarded as more potent against roundworm but poorly suited to weak or deficient patients; combined with Fei Zi and Shi Jun Zi for roundworm (ascariasis).
  • Fei Zi — sweet, astringent, neutral, and oily; the gentlest of the group, does not require purging, and is distinctive for combining anti-parasitic action with intestine-moistening and Lung-moistening effects the others do not share.

  Common combinations (per materia medica references): with Shi Jun Zi and Ku Lian Pi for roundworm (ascariasis); with Bing Lang and Guan Zhong for hookworm (ancylostomiasis); with Bing Lang and Nan Gua Zi for tapeworm (taeniasis); with Wu Mei to calm the parasites before expelling them, easing abdominal pain; with moistening laxative herbs such as Huo Ma Ren for stubborn dry constipation; and with yin-nourishing Lung herbs such as Sha Shen for dry cough. (Traditional formula/combination context, not treatment advice; no formula link for this herb was found in this site’s own record.)

  Source: published materia medica consensus on herb differentiation and combinations (Bensky/Chen & Chen-level texts), cross-referenced against multiple online sources.