Traditionally used for
- Cough & breathing
- Digestion
- Bowel health
☯ TCM Properties
Expels Parasites; Resolves Accumulation; Moistens the Lungs and Stops Cough; Moistens the Intestines and Unblocks the Bowels
Traditional Chinese Uses
Fei Zi (torreya seed, Japanese torreya) is a mild, warm herb used in Chinese medicine to expel intestinal parasites — particularly tapeworms, roundworms, and hookworms — without harming the Spleen and Stomach Qi. Its oily content also moistens the Intestines to relieve dry constipation. As a food-safe antiparasitic with a pleasant nutty flavor, it is one of the more palatable parasite-clearing preparations and is appropriate even for those with weaker digestive constitutions.
Relationships
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Botanical Description
Torreya grandis is an evergreen coniferous tree in the Taxaceae, endemic to subtropical mountainous regions of eastern China, particularly Zhejiang and adjacent provinces, where it grows on shaded slopes between 200 and 1400 meters. Mature trees reach 12 to 25 meters in height, with a broadly conical crown, smooth pale-grey bark fissuring into longitudinal plates with age, and spreading horizontal branches. The leaves are linear, stiff, sharply pointed, 1.1 to 2.5 cm long, arranged in two flat ranks along the shoots, dark glossy green above with two narrow whitish stomatal bands beneath. The species is dioecious; male cones are small and pale yellow, while female cones consist of a single ovule that develops over about eighteen months into a large, drupe-like seed enclosed in a fleshy, greenish-purple aril 2 to 4.5 cm long. The hard inner seed is oily and edible after roasting and constitutes the medicinal Fei Zi, used in traditional Chinese medicine to expel intestinal parasites and moisten the bowels.
Active Constituents
Sciadonic acid (all-cis-5,11,14-eicosatrienoic acid)
Non-methylene-interrupted (delta-5 olefinic) polyunsaturated fatty acidConcentration: eicosatrienoic acid measured at 6.78 to 8.37% of the cold-pressed kernel oil across seven Chinese cultivars
A gymnosperm-specific fatty acid that is the chemical signature of Torreya seed oil, and whose biosynthetic pathway was resolved by the 2023 Torreya grandis genome. It is incorporated into membrane phospholipids in place of arachidonic acid, and because it lacks the geometry needed for cyclooxygenase and lipoxygenase turnover it lowers downstream eicosanoid production. This is the basis of the reported anti-inflammatory and lipid-modifying properties of the oil.
Linoleic acid
Omega-6 polyunsaturated fatty acidConcentration: 39.39 to 47.77% of the cold-pressed kernel oil
The dominant fatty acid of the kernel oil. It carries the bulk of the seed's caloric and nutritional value and, with oleic acid, accounts for the drug's traditional reputation for moistening the intestines.
Oleic acid
Monounsaturated fatty acidConcentration: 30.47 to 37.54% of the cold-pressed kernel oil
The second major fatty acid of the seed. The high total oil content of the kernel, 45.80 to 53.16% by weight, is the mechanistic basis for the classical warning that overdose of Fei Zi produces diarrhoea by over-lubricating the intestines.
Tocopherols (alpha, beta, gamma and delta isomers)
Vitamin E isomers (chromanol)Concentration: 0.64 to 1.77 mg/g of the kernel oil
The endogenous antioxidants that keep the highly unsaturated oil from going rancid, and a meaningful part of the seed's nutritional value.
Beta-sitosterol
PhytosterolConcentration: 0.90 to 1.29 mg/g of kernel oil, with campesterol at 0.06 to 0.32 mg/g and stigmasterol at 0.04 to 0.18 mg/g
The main sterol of the kernel oil, of the class that competes with cholesterol for micellar incorporation and modestly reduces cholesterol absorption.
Miogadial
Drimane-type sesquiterpene dialdehydeConcentration: not quantified in the seed; isolated by bioassay-guided fractionation, IC50 25.1 plus or minus 5.4 micromolar against Caenorhabditis elegans
One of the two compounds identified as responsible for the anthelmintic activity of Semen Torreyae. It is the more potent of the pair and acts synergistically with galangal acetate. Notably, it does not act on the targets of ivermectin, levamisole, benomyl or aldicarb, and worm strains resistant to those drugs are not cross-resistant to it.
Galangal acetate (1'-acetoxychavicol acetate)
Phenylpropanoid diesterConcentration: not quantified in the seed; IC50 58.5 plus or minus 8.9 micromolar against Caenorhabditis elegans
The second anthelmintic principle isolated from Semen Torreyae. Combined with miogadial it gives combination index values below 1 at the IC50, IC70 and IC90 levels, that is, genuine synergy rather than simple additivity.
D-Limonene
Monoterpene (volatile)The dominant volatile of the seed and the source of its characteristic aroma. It has no established role in the anthelmintic action.
⚠ Drug Interactions
Osmotic and stimulant laxatives (macrogol, senna, bisacodyl)
The kernel is roughly half fixed oil by weight, at 45.80 to 53.16%, and the traditional anthelmintic dose is large, conventionally 15 to 50 g of seed. The classical texts describe the drug as moistening the intestines and unblocking the bowels, and the classical caution is that overdose over-lubricates the intestines and causes diarrhoea. That is a straightforward bulk-lipid effect and it will add to any co-administered laxative.
Clinical note: Fei Zi is already contraindicated in patients with loose stools. Do not run it alongside a laxative regimen, and reduce the dose if stools loosen.
Ivermectin, levamisole, albendazole and other conventional anthelmintics
Bioassay-guided work in Caenorhabditis elegans showed that mutant strains resistant to ivermectin, levamisole, benomyl and aldicarb were no more resistant to miogadial or galangal acetate than wild-type worms, and transient receptor potential channel mutants were likewise not resistant. The Torreya principles therefore appear to act on targets distinct from those of the standard anthelmintic classes. This is a worm-model finding and has not been shown in a human infection.
Clinical note: There is no pharmacological reason to expect the seed to blunt a conventional anthelmintic, but there is also no clinical trial evidence that Fei Zi clears any human helminth infection. It should not be offered as a substitute for a proven anthelmintic in confirmed parasitosis.
Antiplatelet agents and NSAIDs (aspirin, clopidogrel, ibuprofen)
Sciadonic acid, 6.78 to 8.37% of the kernel oil, is a delta-5 non-methylene-interrupted fatty acid that displaces arachidonic acid from membrane phospholipids without itself being a usable cyclooxygenase substrate, thereby reducing the pool available for thromboxane and prostaglandin synthesis. This is the same class of mechanism by which fish-oil fatty acids interact with antiplatelet therapy. No bleeding event has been reported with Torreya seed and no human pharmacodynamic study exists, so this is a mechanistic inference only.
Clinical note: No action needed at culinary intakes. If large anthelmintic doses of the seed are used in a patient on dual antiplatelet therapy or anticoagulation, watch for bruising rather than assuming the herb is inert.
Mung bean (Lu Dou)
The standard TCM materia medica records a dietary incompatibility between Fei Zi and mung bean during treatment. No chemical or pharmacological basis has been demonstrated for this and no published study addresses it; it is recorded here because practitioners will encounter it in the classical sources, not because it has been substantiated.
Clinical note: A traditional prohibition without evidential support. Note it if the patient follows classical dietary advice; do not present it to the patient as an established pharmacological interaction.
Dosage
| Form | Amount | Frequency | Duration | Population | Notes |
|---|---|---|---|---|---|
| decoction | 9–15 g | Daily | — | — | 中国药典 2020 【用法与用量】9～15g。 【性味与归经】甘，平。归肺、胃、大肠经。 — Chinese Pharmacopoeia 2020, quoted verbatim; route and cautions preserved. Replaces a cleared category-filler value. |
Evidence Tier
Limited evidence · 1 studyRecorded studies by study design, strongest design at the top. This is a study-design tier only, not a GRADE rating: it does not weigh risk of bias, consistency or precision.
Systematic review / meta-analysis
0
Randomized controlled trial
0
Other clinical trial
0
Observational / case report
0
In vitro / animal
1
1 verified · 0 unverified
Other / unclassified
0
Verified: design read from PubMed for a DOI that resolves to the cited paper Unverified: taken from the study's recorded description
Clinical Studies
Bioassay-guided isolation of active substances from Semen Torreyae identifies two new anthelmintic compounds with novel mechanism of action
Using a Caenorhabditis elegans model, bioassay-guided fractionation of Semen Torreyae, explicitly the seed of Torreya grandis, yielded two anthelmintic compounds: galangal acetate with an IC50 of 58.5 plus or minus 8.9 micromolar and miogadial with an IC50 of 25.1 plus or minus 5.4 micromolar. The combination was synergistic at the IC50, IC70 and IC90 levels. C. elegans strains resistant to ivermectin, levamisole, benomyl and aldicarb showed no cross-resistance, and TRP channel mutants were not resistant either, so the compounds appear to act on a target outside the known anthelmintic classes. This is the first identification of the anthelmintic principles of the drug and remains a nematode-model study, not a clinical one. The paper places Torreya in Cephalotaxaceae; the accepted placement is Taxaceae.
Historical Texts
Shen Nong Ben Cao Jing
Han dynastyReferences
- Zhiyong He, Haidong Zhu, Wangling Li, Maomao Zeng, Shengfang Wu, Shangwei Chen, Fang Qin, Jie Chen. Chemical components of cold pressed kernel oils from different Torreya grandis cultivars . Food Chemistry (2016) [DOI]
- Heqiang Lou, Lili Song, Xiaolong Li, Hailing Zi, Weijie Chen, Yadi Gao, Shan Zheng, Zhangjun Fei, Xuepeng Sun, Jiasheng Wu. The Torreya grandis genome illuminates the origin and evolution of gymnosperm-specific sciadonic acid biosynthesis . Nature Communications (2023) [DOI]
- Ran Liu, Baogang Zhou, Kundian Che, Wei Gao, Haoyuan Luo, Jialin Yang, Zhanjun Chen, Wenzhong Hu. Chemical Composition and Biological Activities of Torreya grandis Kernels: Characteristics of Polymethylene-Interrupted Fatty Acids and Polyphenolic Compounds and Their Potential Health Effects . Forests (2025) [DOI]
This information is for educational purposes only and is not intended to replace professional medical advice. Always consult a qualified healthcare provider before using any herbal remedy, especially if you are pregnant, nursing, or taking medications.
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