Herb Seed (种子 zhǒng zǐ / 子 zǐ / 仁 rén)

Wu Yi

Large-fruited Elm seed paste · 芜荑

Torreya grandis Fort. · Semen Torreyae

Also known as: Chou Wu Yi (臭芜荑)

Wu Yi (Large-fruited Elm seed paste) plant

Images shown are for educational purposes only

Torreya seed is a mild, sweet-tasting herb primarily used to expel intestinal parasites such as tapeworms, roundworms, and hookworms. Unlike many antiparasitic herbs, it is gentle on the body and does not damage Qi or Blood. It also moistens the intestines to relieve constipation and moistens the Lungs to calm dry coughs.

Category Parasite-expelling herbs (驱虫药)
Therapeutic focus Digestive Health Intestinal Parasite Support Constipation Relief Respiratory Health

TCM Properties

Temperature

Neutral

Taste

Sweet (甘 gān), Astringent (涩 sè)

Channels entered

Lungs, Stomach, Large Intestine

Parts used

Seed (种子 zhǒng zǐ / 子 zǐ / 仁 rén)

Educational content • Consult qualified TCM practitioners for diagnosis and treatment

What This Herb Does

Every herb has a specific set of actions — here's what Wu Yi does in the body, explained in both everyday and TCM terms

Therapeutic focus

In practical terms, Wu Yi is primarily used to support these areas of health:

Digestive Health Intestinal Parasite Support Constipation Relief Respiratory Health

TCM Actions

In TCM terminology, these are the specific therapeutic actions that Wu Yi performs to restore balance in the body:

Expels Parasites Resolves Accumulation Moistens the Lungs and Stops Cough Moistens the Intestines and Unblocks the Bowels

How these actions work

'Kills parasites' (杀虫) is the primary action of Torreya seed. It is effective against a range of intestinal worms including tapeworms (especially), roundworms, hookworms, and pinworms. The classical text Ben Cao Xin Bian noted that Torreya seed is the most effective at killing worms. Unlike most antiparasitic herbs, which tend to be bitter and harsh, Torreya seed is sweet and gentle, making it suitable for children and those with weaker constitutions. A classical teaching from Li Shizhen's Ben Cao Gang Mu observes that among worm-killing herbs, only Torreya seed and Shi Jun Zi (Quisqualis) are sweet-tasting yet effective at killing parasites.

'Disperses accumulation' (消积) refers to the herb's ability to address digestive stagnation, particularly in children. When parasites disrupt normal digestion, children may develop a condition called 'gan ji' (childhood nutritional impairment) with symptoms like a distended abdomen, sallow complexion, and poor appetite. Torreya seed helps clear the parasites and resolve the resulting food stagnation.

'Moistens the Lungs and stops coughing' (润肺止咳) takes advantage of the herb's oily, moistening nature. When the Lungs become dry (from dry climate, insufficient fluids, or chronic illness), a persistent dry cough can develop. The rich oil content of Torreya seed gently nourishes Lung moisture to soothe this type of cough.

'Moistens the intestines and unblocks the bowels' (润肠通便) is another function of the seed's high oil content. The oils lubricate the intestinal walls, making it useful for dry-type constipation. This secondary action also helps expel dead parasites after the herb's antiparasitic effect takes hold.

Patterns Addressed

In TCM, symptoms cluster into recognizable patterns of disharmony. Wu Yi is used to help correct these specific patterns.

Why Wu Yi addresses this pattern

Torreya seed directly kills intestinal parasites through its antiparasitic compounds. Its sweet, neutral nature means it accomplishes this without the harsh side effects of many bitter, cold antiparasitic herbs. The herb enters the Stomach and Large Intestine channels, placing its action precisely where intestinal parasites reside. Its oily, slightly laxative quality also helps expel dead worms from the body. Classical sources specifically highlight its effectiveness against tapeworms ('cun bai chong'), with the Shi Liao Ben Cao recommending seven seeds daily for seven days to eliminate tapeworms.

A practitioner would look for one or more of these signs

Abdominal Pain

Colicky abdominal pain that comes and goes, often around the navel

Loss Of Appetite

Poor appetite despite eating, failure to gain weight

Parasitic Infestation

Visible worms in stool or vomit

Commonly Used For

These are conditions where Wu Yi is frequently used — but only when they arise from the specific patterns it addresses, not in all cases

Arises from: Intestinal Parasite

TCM Interpretation

In TCM, intestinal parasite infections are understood as arising when the Spleen and Stomach become weak or when Damp-Heat accumulates in the intestines, creating an environment where parasites ('chong') can thrive. The parasites themselves then further damage the Spleen's ability to transform food, leading to a vicious cycle of malabsorption, stagnation, and worsening infestation. In children, the Spleen is considered inherently immature, which explains their higher susceptibility. The parasites cause Qi to stagnate in the intestines, producing the characteristic colicky, intermittent abdominal pain.

Why Wu Yi Helps

Torreya seed's antiparasitic compounds directly kill intestinal worms. Its sweet, neutral nature makes it exceptionally well-suited for this condition because it eliminates parasites without further damaging the already weakened Spleen Qi. The Ben Cao Xin Bian specifically noted that unlike most antiparasitic substances which injure Qi and Blood, Torreya seed does not. Its oil content provides a mild laxative effect that helps expel dead parasites. Clinical reports have shown efficacy against hookworm, tapeworm, roundworm, and even filariasis when used in sufficient doses over several weeks.

Also commonly used for

Dry Cough

Dry cough from Lung dryness

Hemorrhoids

Hemorrhoids with constipation

Malnutrition

Childhood nutritional impairment (gan ji) from parasite infestation

Abdominal Pain

Abdominal pain due to intestinal parasites

Herb Properties

Every herb has an inherent temperature, taste, and affinity for specific channels — these properties determine how it interacts with the body

Temperature

Neutral

Taste

Sweet (甘 gān), Astringent (涩 sè)

Channels Entered

Lungs Stomach Large Intestine

Parts Used

Seed (种子 zhǒng zǐ / 子 zǐ / 仁 rén)

Dosage & Preparation

These are general dosage guidelines for Wu Yi — always follow your practitioner's recommendation, as dosages vary based on the formula and your individual condition

Standard dosage

3-10g

Maximum dosage

10g in decoction. Do not exceed standard range without practitioner supervision, as excessive doses may damage Stomach Qi and have shown toxicity in animal studies.

Dosage notes

For decoction, 3-10g is standard. When taken as pills or powder, the typical single dose is 2-3g. For topical application to scabies or tinea, the powdered herb is mixed with vinegar or honey and applied to the affected area in appropriate amounts. The herb works well when combined with He Zi (Terminalia chebula) and Dou Kou (Amomum) for enhanced effect, as noted in the Hai Yao Ben Cao. For killing intestinal parasites, Wu Yi is often combined with Bing Lang (betel nut) and other antiparasitic herbs rather than used alone.

Preparation

Wu Yi undergoes a unique traditional processing method before medicinal use. The seeds are collected from the ripe winged fruits, soaked in water until fermented, then mixed with elm bark powder, red earth (clay), and chrysanthemum flower powder. This mixture is blended into a paste, spread flat, cut into square blocks, and dried. This fermentation and processing is essential to the herb's medicinal identity. The resulting processed blocks can then be decocted normally or ground into powder for pills.

Processing Methods

In TCM, the same herb can be prepared in different ways to change its effects — here's how processing alters what Wu Yi does

Processing method

The raw seed kernels are dry-fried (or sand-fried) until the surface turns dark yellow to brownish-black with some charred spots, the interior turns yellow, and a fragrant aroma develops. If sand-frying, hot sand is added to the wok first, then the seeds are stirred until they pop and darken, after which the sand is sieved away.

How it changes properties

Dry-frying makes the seed slightly warmer and enhances its ability to strengthen the Spleen and disperse food stagnation. The raw form is better for its antiparasitic and moistening actions, while the dry-fried form is preferred when childhood nutritional impairment (gan ji) with Spleen weakness is the primary concern. The processing also improves digestibility and makes the seed more palatable for direct consumption by chewing.

When to use this form

Preferred for childhood nutritional impairment with food stagnation, poor appetite, and a weak Spleen. Also used when the seeds will be chewed and eaten directly (rather than decocted), as the frying enhances flavour and digestibility. For hookworm treatment, clinical protocols typically use the dry-fried form eaten in large quantities.

Common Herb Pairs

These ingredients are traditionally combined with Wu Yi for enhanced therapeutic effect

Shi Jun Zi
Shi Jun Zi 1:1 (e.g. Fei Zi 30g : Shi Jun Zi 30g)

Both herbs are sweet-tasting antiparasitic agents that kill intestinal worms without damaging Qi and Blood. Together they broaden the spectrum of antiparasitic activity: Shi Jun Zi is particularly effective against roundworms (hui chong), while Fei Zi has a special strength against tapeworms (tao chong/cun bai chong). The combination also addresses the childhood nutritional impairment that often accompanies chronic parasitic infection.

When to use: Mixed intestinal parasite infections in children, especially when accompanied by poor appetite, sallow complexion, and abdominal distension.

Bing Lang
Bing Lang 1:1 (e.g. Fei Zi 30g : Bing Lang 30g)

Fei Zi kills parasites while Bing Lang (Areca/Betel nut) both kills parasites and promotes their downward expulsion through its Qi-moving, mildly purgative action. Fei Zi is gentle and moistening, while Bing Lang is more forceful at driving things downward. Together, they kill a wide range of worms and ensure their effective elimination from the body.

When to use: Tapeworm and other intestinal parasite infections where both killing and active expulsion of the worms is needed. This is a classical combination found in the Fei Zi San formula.

Wu Yi
Wu Yi 1:1

Fei Zi and Wu Yi (Ulmus fruit/芜荑) are both antiparasitic herbs that work through different mechanisms. Wu Yi (Ulmus) is warm and acrid, helping to disperse and kill parasites through its warming, drying action, while Fei Zi is neutral and moistening. Together they cover both Damp and Dry intestinal environments where parasites may reside.

When to use: Intestinal parasites with mixed presentations, especially tapeworm and roundworm infections. This combination appears in the classical Fei Zi San formula alongside Bing Lang.

Huo Ma Ren
Huo Ma Ren 1:1

Both herbs are oily seeds that moisten and lubricate the intestines. Fei Zi adds mild antiparasitic action while Huo Ma Ren (hemp seed) is a stronger intestinal moistener. Together they provide enhanced lubrication for stubborn dry constipation.

When to use: Chronic dry constipation, especially in elderly patients or those with Blood/Yin Deficiency leading to intestinal dryness.

Comparable Ingredients

These ingredients have overlapping uses — here's how to tell them apart

Shi Jun Zi
Wu Yi vs Shi Jun Zi

Both are sweet-tasting, gentle antiparasitic herbs that do not damage Qi and Blood, making them uniquely suited for children and weak patients. However, Shi Jun Zi is warm and particularly effective against roundworms (hui chong), while Fei Zi is neutral and has a special reputation for killing tapeworms (tao chong). Fei Zi also has secondary actions of moistening the Lungs and intestines that Shi Jun Zi lacks. The Ben Cao Zheng noted: 'Shi Jun Zi specializes in killing roundworms, while Fei Zi specializes in killing tapeworms.'

Bing Lang
Wu Yi vs Bing Lang

Both expel intestinal parasites, but through very different mechanisms. Bing Lang (Areca) is acrid and bitter, strongly moves Qi downward, and has a purgative action that forcefully expels worms. Fei Zi is sweet, gentle, and moistening, killing parasites without harsh side effects. Bing Lang is better for acute, severe infestations requiring forceful expulsion, while Fei Zi is preferred for milder cases, in children, or in constitutionally weak patients who cannot tolerate Bing Lang's harsh, downward-driving nature.

Ku Lian Pi
Wu Yi vs Ku Lian Pi

Ku Lian Pi (Melia bark) is bitter, cold, and toxic, making it a powerful but potentially dangerous antiparasitic that must be used with caution and only short-term. Fei Zi is sweet, neutral, and non-toxic, making it much safer for prolonged use and in vulnerable patients such as children. For severe infestations, Ku Lian Pi is more potent; for mild to moderate cases or when safety is a priority, Fei Zi is preferred.

Common Substitutes & Adulterants

Related species and common adulterations to be aware of when sourcing Wu Yi

The most important distinction is between 'large Wu Yi' (大芜荑, from Ulmus macrocarpa, the true medicinal product) and 'small Wu Yi' (小芜荑, ordinary elm seeds from Ulmus pumila, the common elm). Only the large variety should be used medicinally. The Ben Cao Yan Yi specifically warns about this confusion. Additionally, the traditional processed product involves fermentation of the seeds mixed with elm bark, red earth, and chrysanthemum powder. Commercially, the proportions of these additives vary, and poor-quality products may contain excessive amounts of filler (red earth) relative to actual seed content. Salt-preserved Wu Yi, though common as a food product, is unsuitable for medicinal use as the salt damages its therapeutic properties.

Educational content — always consult a qualified healthcare provider or TCM practitioner before using any herb.

Toxicity Classification

Classical Chinese pharmacopoeia toxicity rating for Wu Yi

Non-toxic

The Hai Yao Ben Cao (《海药本草》) records Wu Yi as non-toxic. However, animal studies have shown that excessively large doses can be harmful. In one experiment, a cat given 10% Wu Yi decoction at 24ml/kg/day died five days after treatment ended, likely from overdose toxicity. The herb's volatile oil showed no toxicity in rabbits at 1g/kg orally. At standard human dosages (3-10g), Wu Yi is considered safe when used for appropriate indications and limited duration. Prolonged use at higher doses may injure Stomach Qi.

Contraindications

Situations where Wu Yi should not be used or requires extra caution

Caution

Spleen and Stomach deficiency with weakness: Wu Yi's bitter, pungent, and dispersing nature can further injure an already weak digestive system. As the Ben Cao Cong Xin states, even if there is accumulation, do not use Wu Yi indiscriminately when the Spleen and Stomach are deficient.

Caution

Dryness-Heat in the Lungs or Spleen: Wu Yi's warm, drying nature can aggravate conditions where the Lungs or Spleen already have excessive dryness and heat.

Caution

Prolonged or excessive use: Wu Yi's strongly dispersing and driving nature can damage Stomach Qi with long-term or high-dose use. Treatment should stop once the parasitic or accumulation condition resolves.

Special Populations

Important considerations for pregnancy, breastfeeding, and pediatric use

Pregnancy

No specific classical contraindication for pregnancy has been recorded. However, Wu Yi's strongly dispersing, pungent, and bitter nature and its function of driving out parasites and accumulations suggest caution during pregnancy. Its warming and downward-driving actions could theoretically disturb the fetus. Pregnant women should avoid use unless specifically directed by a qualified practitioner.

Breastfeeding

No specific classical data exists on Wu Yi during breastfeeding. Given its strong parasite-expelling and accumulation-dispersing properties, and the possibility that active compounds (tannins, volatile oils) could pass into breast milk, caution is advised. Use only when clearly indicated and under practitioner supervision, keeping to the lowest effective dose for the shortest necessary duration.

Children

Wu Yi has a long history of pediatric use, particularly for childhood malnutrition (gan ji, 疳积) with parasites. Classical formulas like Bu Dai Wan and Lu Hui Fei Er Wan include Wu Yi as a key ingredient for malnourished children with worms. For children, dosages should be significantly reduced from the adult range. Classical sources suggest approximately 0.5-1.5g per dose for young children, adjusted by age and weight. The herb should only be used when there is clear evidence of parasitic infection or food accumulation, not as a general tonic, and treatment should be stopped once the condition resolves.

Drug Interactions

If you are taking pharmaceutical medications, be aware of these potential interactions with Wu Yi

No well-documented pharmaceutical drug interactions have been established for Wu Yi in modern clinical literature. The herb contains tannins, which theoretically could reduce the absorption of orally administered medications (particularly iron supplements, alkaloid-based drugs, and some antibiotics) if taken concurrently. As a general precaution, Wu Yi should be taken at least two hours apart from any pharmaceutical medications.

Dietary Advice

Foods and dietary considerations when taking Wu Yi

Avoid cold, raw foods during treatment, as Wu Yi is used for conditions involving cold accumulation and parasites in the digestive tract, and cold foods would counteract its warming action. Avoid salt-heavy foods, as excessive salt can interfere with Wu Yi's therapeutic properties. Combining Wu Yi treatment with easily digestible, warming foods supports its action of restoring healthy digestive function.

Botanical Description

Physical characteristics and morphology of the Wu Yi source plant

Wu Yi comes from the large-fruited elm (Ulmus macrocarpa Hance), a deciduous tree or sometimes large shrub in the Ulmaceae (elm) family that can reach up to 20 metres tall with a trunk diameter of 40 cm. The bark is dark grey to greyish-black and roughly furrowed with longitudinal fissures. Young branches are pale yellowish-brown with sparse hairs, and the twigs often bear distinctive flat, corky wings on two or four sides.

The leaves are thick and leathery, broadly obovate to rounded, 5 to 9 cm long, with coarsely double-serrated margins and a rough texture on both surfaces covered in stiff hairs. The winged fruits (samaras) are large and rounded, 2.5 to 3.5 cm across, ripening in April to May. The tree is light-loving, cold-hardy, and drought-tolerant, growing naturally on mountain slopes, valleys, loess hills, and rocky crevices at elevations up to 1,800 metres in northern China.

Sourcing & Harvesting

Where Wu Yi is sourced, when it's harvested or collected, and how to assess quality

Harvesting season

Summer (May to June), when the winged fruits have matured.

Primary growing regions

The primary production regions are Shanxi (山西) and Hebei (河北) provinces, which are traditionally considered to produce the best quality. The Shen Nong Ben Cao Jing notes it as originating from Jin Mountain (晋山). Significant production also comes from the three northeastern provinces (Heilongjiang, Jilin, Liaoning) and Shaanxi. The tree grows widely across northeast and north China, extending into parts of the northwest and northern Jiangsu.

Quality indicators

The processed medicinal product (Wu Yi paste) appears as flat, square blocks. The surface should be brownish-yellow to brownish-brown with numerous small holes and pores, with visible fibers and seeds throughout. The texture is loose, brittle, and coarse, and the cross-section is yellowish-black. It breaks apart in layers easily. The taste is mildly sour and astringent, and the product has a characteristic strong, unpleasant (stinking) odour. Aged product is considered superior to fresh. Avoid material that has been salt-preserved, as this destroys the essential properties and makes it unsuitable for medicinal use.

Classical Texts

Key passages from the classical Chinese medical texts that describe Wu Yi and its therapeutic uses

Shen Nong Ben Cao Jing (《神农本草经》)

Original: 主五内邪气散，皮肤骨节中，淫淫温行毒，去三虫，化食。

Translation: It governs pathogenic Qi in the five Zang organs, disperses toxins moving through the skin and bony joints, eliminates the three types of parasitic worms, and transforms food [stagnation].

Ben Cao Jing Shu (《本草经疏》)

Original: 芜荑，非辛温则不能散五脏、皮肤、骨节中邪毒气，非苦平则不能去三虫、化食、逐寸白，疗肠中温温喘息。然察其所主，虽能除风淫邪气之为害，而其功则长于走肠胃，杀诸虫，消食积也。故小儿疳泻冷痢为必资之药。

Translation: Wu Yi requires its pungent warmth to disperse pathogenic toxin Qi from the five organs, skin, and bony joints, and its bitter balanced nature to eliminate the three worms, transform food, and expel tapeworm segments. Although it can address damage from wind and pathogenic Qi, its strength lies particularly in traversing the intestines and stomach to kill parasites and dissolve food accumulation. Thus it is an essential herb for childhood malnutrition with diarrhea and cold-type dysentery.

Ben Jing Feng Yuan (《本经逢原》)

Original: 芜荑辛散，能祛五内皮肤骨节湿热之病。近世但知其有去疳杀虫及治肠风痔痿、恶疮疥癣之用，殊失《本经》之旨。

Translation: Wu Yi is pungent and dispersing, able to expel damp-heat disease from the five organs, skin, and bony joints. Modern practitioners only know it for eliminating childhood malnutrition, killing parasites, and treating intestinal wind with hemorrhoids and scabies, which entirely misses the original intent of the Ben Jing.

Historical Context

The history and evolution of Wu Yi's use in Chinese medicine over the centuries

Wu Yi has an ancient pedigree as a medicinal substance, first recorded in the Shen Nong Ben Cao Jing (《神农本草经》), where it was classified in the lower grade (下品). The Er Ya (《尔雅》), one of China's oldest dictionaries, records the tree under the name Wu Gu (无姑), while Guo Pu's commentary identifies it as Gu Yu (姑榆, 'aunt elm'). The Shuo Wen Jie Zi calls it Shan Fen Yu (山粉榆, 'mountain powder elm'). The name Wu Yi (芜荑) likely derives from the plant's distinctively foul, musty odour when the seeds are fermented for processing.

Beyond its medicinal use, Wu Yi had a notable culinary history. Tao Hongjing noted in the Ben Cao Jing Ji Zhu that people commonly made it into a sauce (酱) for eating. The Ben Cao Yan Yi distinguished between 'large Wu Yi' (the true medicinal product from Ulmus macrocarpa) and 'small Wu Yi' (ordinary elm seed from Ulmus pumila), warning that only the large variety should be used medicinally. Li Shizhen in the Ben Cao Gang Mu further elaborated that the small variety was commonly made into a condiment but was often adulterated, cautioning users to pick out impurities. The herb also features prominently in pediatric medicine, appearing in Qian Yi's famous Xiao Er Zhi Jue (《小儿直诀》) for treating childhood malnutrition with parasites.