Ingredient Animal — secretion (动物分泌物 dòng wù fēn mì wù)

Wu Ling Zhi

Flying squirrel feces · 五灵脂

Trogopterus xanthipes Milne-Edwards · Faeces Trogopterori

Also known as: Ling Zhi (灵脂)

Wu Ling Zhi (Flying squirrel feces) plant

Images shown are for educational purposes only

Wu Ling Zhi is a warming herb derived from flying squirrel droppings, primarily used to relieve pain caused by blood stasis. It is commonly applied for menstrual cramps, postpartum abdominal pain, chest pain, and stomach pain. When stir-fried, it also helps stop bleeding that is accompanied by blood stasis, such as heavy or irregular periods.

Category Blood-invigorating and stasis-dispelling herbs (活血化瘀药) Blood-invigorating and pain-relieving herbs (活血止痛药)
Therapeutic focus Pain Management Menstrual Health Cardiovascular Health Digestive Health

TCM Properties

Temperature

Warm

Taste

Bitter (苦 kǔ), Sweet (甘 gān), Salty (咸 xián)

Channels entered

Liver, Spleen

Parts used

Animal — secretion (动物分泌物 dòng wù fēn mì wù)

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Educational content • Consult qualified TCM practitioners for diagnosis and treatment

What This Ingredient Does

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

Therapeutic focus

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

Pain Management Menstrual Health Cardiovascular Health Digestive Health

TCM Actions

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

Invigorates Blood and Alleviates Pain Dispels Stasis and Stops Bleeding Resolves Accumulation Resolves Toxicity

How these actions work

'Invigorates Blood and alleviates pain' means Wu Ling Zhi actively promotes blood circulation and breaks up areas where blood has become stagnant and stuck. In TCM, when blood stops flowing smoothly, it causes sharp, stabbing, or fixed-location pain. Wu Ling Zhi enters the Liver channel's blood level and opens up the blood vessels to disperse stagnant blood, which is why it is considered an essential herb for any pain condition caused by blood stasis. This applies to menstrual cramps, postpartum abdominal pain, chest pain (as in angina), and stomach pain with a stabbing quality.

'Transforms stasis and stops bleeding' applies specifically to the stir-fried (炒) form of Wu Ling Zhi. When processed by dry-frying, the herb gains the ability to both break up old stagnant blood and stop abnormal bleeding at the same time. This dual action is particularly valuable when bleeding is caused by blood stasis, meaning the blood is not flowing in its proper channels. It is used for conditions like heavy menstrual bleeding with dark clots and lower abdominal pain, or uterine bleeding (崩漏) that has not responded to other treatments. The classical teaching states: 'use raw to move blood, use stir-fried to stop blood' (行血宜生，止血须炒).

'Resolves accumulation and eliminates toxins' refers to Wu Ling Zhi's secondary ability to treat childhood nutritional impairment (疳积), where poor digestion leads to accumulation and malnutrition. It also has a traditional use as an antidote for snake, scorpion, and centipede bites, applied both internally and externally with substances like realgar (雄黄).

Patterns Addressed

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

Why Wu Ling Zhi addresses this pattern

Wu Ling Zhi is a primary herb for Blood Stagnation because its bitter taste promotes downward movement and dispersion, its sweet taste moderates harshness, and its warm temperature activates sluggish blood flow. Entering the Liver channel's blood level, it directly addresses the Liver's role in ensuring the smooth flow of blood. When blood stagnates in the vessels, it causes sharp, stabbing, or fixed-location pain and can block menstrual flow. Wu Ling Zhi's core action of invigorating blood and alleviating pain makes it one of the most important herbs for any pain condition rooted in blood stasis, whether in the chest, epigastrium, abdomen, or uterus.

A practitioner would look for one or more of these signs

Chest Pain

Stabbing chest pain with fixed location

Abdominal Pain

Epigastric or abdominal pain that is sharp and piercing

Painful Periods

Menstrual pain with dark clotted blood

Amenorrhea

Absence of menstruation due to blood stasis blocking the uterus

Commonly Used For

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

Arises from: Food Stagnation in the Stomach Blood Stagnation

TCM Interpretation

TCM understands painful periods (dysmenorrhea) as most commonly resulting from obstruction in the uterus and its associated channels. When blood fails to flow smoothly through the uterus during menstruation, the blockage creates pain, following the principle 'where there is no free flow, there is pain' (不通则痛). The most common pattern is blood stasis in the uterus, often complicated by cold congealing the blood or Liver Qi stagnation impeding blood flow. Key signs pointing to blood stasis as the root cause include pain that is stabbing or cramping, worsens with pressure, and is accompanied by dark menstrual blood with clots. Pain typically begins before or at the start of flow and improves once clots are passed.

Why Wu Ling Zhi Helps

Wu Ling Zhi directly targets the blood stasis that drives painful periods. Its warm nature counters the cold that often congeals blood in the lower abdomen, while its bitter taste promotes downward movement and dispersion of stagnant blood. Entering the Liver channel, which governs menstruation and the smooth flow of blood, Wu Ling Zhi opens blocked blood vessels in the pelvic region and disperses accumulated clots. This restores normal blood flow through the uterus, relieving the 'no free flow' that causes the pain. It is most commonly paired with Pu Huang (cattail pollen) in the classical formula Shi Xiao San, where the two herbs work synergistically to move stagnant blood and stop pain.

Also commonly used for

Amenorrhea

Absence of menses caused by blood stasis obstructing the uterus

Irregular Menstruation

Menstrual irregularity with dark, clotted blood

Heavy Periods

Menorrhagia with blood clots (stir-fried form)

Postpartum Abdominal Pain

Pain from retained lochia after childbirth

Abdominal Pain

Epigastric and abdominal pain of blood stasis origin

Endometriosis

Pelvic pain and masses from endometrial tissue growth

Trauma

Swelling and pain from bruising and sprains

Ingredient Properties

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

Temperature

Warm

Taste

Bitter (苦 kǔ), Sweet (甘 gān), Salty (咸 xián)

Channels Entered

Liver Spleen

Parts Used

Animal — secretion (动物分泌物 dòng wù fēn mì wù)

Dosage & Preparation

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

Standard dosage

3–10g

Maximum dosage

Up to 15g in acute Blood stasis pain, under practitioner supervision. Do not exceed standard range without clinical justification.

Dosage notes

Use raw (生五灵脂) to invigorate Blood and relieve pain due to Blood stasis, such as in dysmenorrhea, postpartum abdominal pain, chest pain, or epigastric pain. Use dry-fried (炒五灵脂) or charred to stop bleeding with stasis, such as in uterine bleeding with clots and stabbing pain. Vinegar-processed Wu Ling Zhi (醋灵脂) enhances its ability to enter the Liver channel, strengthening both its pain-relieving and Blood-harmonizing effects. When used as powder (taken directly with warm water or wine), the typical dose is 1.5–3g per serving. In decoction, 3–10g is standard. Larger doses towards the upper range may be used for acute Blood stasis pain.

Preparation

Wu Ling Zhi should ideally be wrapped in cloth (包煎) when decocted, because its fine particles and fibrous material can make the decoction cloudy and difficult to strain. This is especially important for the granular form (Ling Zhi Mi). Alternatively, it may be ground into powder and taken directly with warm water or wine rather than decocted. When used raw in decoction, it should be rinsed with water first to remove sand and impurities.

Processing Methods

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

Processing method

Stir-fry clean Wu Ling Zhi in a hot wok until warm, then spray with rice vinegar and continue stir-frying until slightly dry with a slight sheen on the surface. The typical ratio is 100g of vinegar per 100g of herb.

How it changes properties

Vinegar processing enhances the herb's ability to enter the Liver channel and strengthens its blood-invigorating and pain-stopping actions. The vinegar also moderates the herb's strong, unpleasant smell and reduces its tendency to upset the stomach. The thermal nature remains warm. This is the most commonly dispensed form in modern practice.

When to use this form

The standard form for most clinical applications. Choose vinegar-processed Wu Ling Zhi when the primary goal is to invigorate blood and relieve pain, especially for menstrual pain, postpartum pain, and epigastric pain from blood stasis.

Common Ingredient Pairs

These ingredients are traditionally combined with Wu Ling Zhi for enhanced therapeutic effect

Pu Huang
Pu Huang 1:1 (typically 6g each)

The most famous herb pair in TCM for blood stasis pain. Wu Ling Zhi specializes in dispersing stagnant blood and stopping pain, while Pu Huang excels at transforming stasis and stopping bleeding. Together they form a synergistic combination (相须) that powerfully opens blood vessels, disperses clots, and alleviates pain. This is the entire composition of the celebrated formula Shi Xiao San (Sudden Smile Powder).

When to use: Any pain condition caused by blood stasis: menstrual cramps, postpartum abdominal pain from retained lochia, epigastric stabbing pain, chest pain from blood stasis, or abnormal uterine bleeding with clots (use stir-fried forms for bleeding).

Yan Hu Suo
Yan Hu Suo 1:1 (typically 6-10g each)

Wu Ling Zhi primarily moves blood stasis, while Yan Hu Suo (Corydalis) is the strongest pain-relieving herb in the Materia Medica that works by both moving blood and regulating Qi. Together they address pain from combined Qi stagnation and blood stasis, producing stronger analgesia than either herb alone. This pairing appears in Shou Nian San (Hand-Grasped Powder).

When to use: Severe stabbing pain in the chest, epigastrium, or abdomen where both Qi stagnation and blood stasis are present. Particularly useful for gastric pain and angina.

Rou Gui
Rou Gui 2:1 (Wu Ling Zhi 6g : Rou Gui 3g)

Wu Ling Zhi disperses stagnant blood while Rou Gui (Cinnamon bark) warms the channels and expels cold. Together they address blood stasis caused or worsened by cold congealing the blood, particularly in the lower abdomen. Rou Gui's warming, channel-penetrating nature drives Wu Ling Zhi's blood-moving action deeper into the pelvic region.

When to use: Painful periods or lower abdominal pain worsened by cold, with dark clotted menstrual blood. This combination appears within Shao Fu Zhu Yu Tang for cold-congealed blood stasis in the lower abdomen.

Jiang Xiang
Jiang Xiang 1:1 (typically 5-6g each)

Wu Ling Zhi opens blood vessels and disperses stasis, while Jiang Xiang (Dalbergia heartwood) invigorates blood and moves Qi with its aromatic nature. Together they combine blood-moving and Qi-regulating actions to produce stronger pain relief for chest and abdominal pain from combined Qi stagnation and blood stasis.

When to use: Chest pain (angina) or abdominal pain where blood stasis and Qi stagnation are intertwined. Also used for traumatic injury with swelling and pain.

Key Formulas

These well-known formulas feature Wu Ling Zhi in a prominent role

Shi Xiao San 失笑散 King

Shi Xiao San (Sudden Smile Powder) is the definitive formula for Wu Ling Zhi, consisting of just two herbs: Wu Ling Zhi and Pu Huang in equal parts. It is the most iconic showcase of Wu Ling Zhi's core blood-invigorating and pain-relieving action. The formula treats any pain caused by blood stasis and is so effective that patients are said to smile with relief upon taking it. From the Tai Ping Hui Min He Ji Ju Fang.

Shao Fu Zhu Yu Tang 少腹逐瘀汤 King

In Shao Fu Zhu Yu Tang (Lower Abdomen Blood Stasis Decoction) from Wang Qing Ren's Yi Lin Gai Cuo, Wu Ling Zhi serves as co-King alongside Pu Huang (together forming the embedded Shi Xiao San). This formula showcases Wu Ling Zhi's application for cold-congealed blood stasis in the lower abdomen, treating painful periods, infertility, and pelvic masses. It is hailed as the 'first formula for regulating menstruation and promoting conception.'

Comparable Ingredients

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

Ru Xiang
Wu Ling Zhi vs Ru Xiang

Both Wu Ling Zhi and Ru Xiang (Frankincense) invigorate blood and stop pain caused by blood stasis, and they are both key herbs for blood stasis pain. However, Wu Ling Zhi is stronger at dispersing deeply lodged stagnant blood (especially in the uterus and pelvic region) and has an additional ability to stop bleeding when stir-fried. Ru Xiang is better at moving Qi alongside blood and also promotes tissue healing and reduces swelling, making it more suited for traumatic injuries, sores, and wounds. Ru Xiang is often paired with Mo Yao (Myrrh) rather than used alone.

Pu Huang
Wu Ling Zhi vs Pu Huang

Both herbs invigorate blood, disperse stasis, and stop pain, and they are most famous as a pair in Shi Xiao San. Used individually, Wu Ling Zhi (bitter, warm) is the stronger pain reliever and focuses on dispersing deep blood stasis, while Pu Huang (sweet, neutral) is the stronger hemostatic agent and also has additional actions of promoting urination and treating urinary tract conditions. For primarily pain conditions, Wu Ling Zhi takes the lead; for bleeding with stasis, Pu Huang is often primary.

Yan Hu Suo
Wu Ling Zhi vs Yan Hu Suo

Both are top-tier pain-relieving herbs for blood stasis, but they work through different mechanisms. Wu Ling Zhi (warm, enters Liver blood level) is stronger at physically dispersing accumulated stagnant blood and clots. Yan Hu Suo (warm, enters Liver and Heart) has stronger analgesic properties and works equally on both Qi stagnation and blood stasis pain. For pain that is primarily from blood stasis with visible clots, Wu Ling Zhi is preferred; for generalized sharp pain from mixed Qi and blood stagnation, Yan Hu Suo may be more versatile.

Common Substitutes & Adulterants

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

The authentic source animal, Trogopterus xanthipes, has become increasingly rare and is now listed as Endangered by the IUCN. Some reports indicate that the feces of wild field rats or other rodent species have been substituted for genuine Wu Ling Zhi in parts of China. Bat feces (Ye Ming Sha, 夜明砂, from insectivorous bats) is a different medicinal substance with different properties and should not be confused with Wu Ling Zhi. The feces of the Siberian flying squirrel (Pteromys volans) has historically been used as a secondary source and is listed in some pharmacopoeias, though Trogopterus xanthipes remains the official standard. Authentic Wu Ling Zhi can be identified by its characteristic elongated pellet shape, fibrous cross-section showing plant material (from arborvitae and pine), and its specific musky odour distinct from bat guano.

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

Toxicity Classification

Classical Chinese pharmacopoeia toxicity rating for Wu Ling Zhi

Non-toxic

Wu Ling Zhi is classified as non-toxic in traditional sources. However, because it is an animal fecal product, quality and hygiene are important considerations. Modern research has identified that the feces of wild flying squirrels may harbour zoonotic pathogens including Leptospira and Blastocystis. Proper processing (cleaning, drying, and stir-frying with vinegar or wine) and standard decoction preparation help mitigate these concerns. The primary safety issue is not toxicity per se but rather the herb's strong Blood-moving properties, which make it unsuitable for those with Blood deficiency or during pregnancy. Overdose may cause gastrointestinal discomfort.

Contraindications

Situations where Wu Ling Zhi should not be used or requires extra caution

Avoid

Pregnancy. Wu Ling Zhi is a Blood-invigorating herb that can stimulate uterine contractions. It should not be used during pregnancy due to the risk of disturbing the fetus or inducing miscarriage.

Avoid

Blood deficiency without Blood stasis. Classical sources including the Ben Cao Jing Shu warn against use when pain or bleeding is due to Blood deficiency rather than Blood stasis, as the herb's strong Blood-moving action can further deplete Blood.

Caution

Concurrent use with Ren Shen (Ginseng). Wu Ling Zhi is listed in the classical Nineteen Mutual Fears (十九畏) as mutually antagonistic with Ren Shen. Most practitioners avoid combining them unless deliberately indicated and supervised.

Caution

Active hemorrhage without underlying Blood stasis. While charred Wu Ling Zhi can stop bleeding, the raw form primarily moves Blood and could worsen bleeding that is not caused by Blood stasis.

Caution

Spleen and Stomach deficiency with poor digestion. The herb has a strong smell and taste that can burden a weak digestive system. Use with caution or combine with Spleen-supporting herbs.

Classical Incompatibilities

Traditional Chinese pharmacological incompatibilities — herbs or substances to avoid combining with Wu Ling Zhi

Wu Ling Zhi appears on the classical Nineteen Mutual Fears (十九畏) list: Ren Shen (人参, Ginseng) fears Wu Ling Zhi (人参畏五灵脂). This means the two substances are traditionally considered antagonistic and should generally not be combined. Some historical practitioners have deliberately used Ren Shen and Wu Ling Zhi together (e.g. Dang Shen with Wu Ling Zhi to tonify the Spleen and stop pain), but this requires careful clinical judgment and should not be done casually.

Special Populations

Important considerations for pregnancy, breastfeeding, and pediatric use

Pregnancy

Contraindicated during pregnancy. Wu Ling Zhi is a potent Blood-invigorating herb with demonstrated effects on uterine smooth muscle. Laboratory studies show it can cause short-term increases in uterine tone. Its strong Blood-moving and stasis-dispersing properties pose a risk of disturbing fetal stability or inducing uterine contractions. The Ben Cao Jing Shu explicitly warns against its use in conditions without Blood stasis, which includes routine pregnancy support.

Breastfeeding

Caution is advised during breastfeeding. Although there are no specific classical prohibitions for breastfeeding mothers, Wu Ling Zhi's Blood-moving properties mean it should only be used when clearly indicated by a Blood stasis pattern. There is insufficient data on whether active compounds transfer into breast milk. Use only under practitioner supervision and for short durations when clinically necessary.

Children

Wu Ling Zhi has a classical application for childhood nutritional impairment (gan ji, 疳积), particularly when accompanied by food stagnation, parasites, and abdominal distension. In such cases it is used in combination with digestive and anti-parasitic herbs. Dosage for children should be reduced proportionally according to age and body weight, generally one-third to one-half of the adult dose. Due to its strong taste and smell, it may be better tolerated in pill or powder form than as a decoction. Not suitable for infants.

Drug Interactions

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

Anticoagulant and antiplatelet medications: Wu Ling Zhi contains flavonoids and other compounds with demonstrated antithrombin and antiplatelet aggregation activity. Concurrent use with warfarin, heparin, aspirin, clopidogrel, or other blood-thinning medications may increase the risk of bleeding. Patients on such medications should inform their healthcare providers before using Wu Ling Zhi.

Ginseng-containing supplements and formulas: Per the classical Nineteen Mutual Fears, Wu Ling Zhi may antagonise the effects of Ren Shen (Ginseng). Patients taking ginseng products (including red ginseng, American ginseng supplements, or ginseng-containing formulas) should be aware of this traditional incompatibility.

Dietary Advice

Foods and dietary considerations when taking Wu Ling Zhi

Avoid cold and raw foods while taking Wu Ling Zhi, as they can impede Blood circulation and counteract the herb's warming, Blood-moving effects. Moderate consumption of warming foods such as ginger, moderate amounts of rice wine, and well-cooked meals supports the herb's therapeutic action. Avoid excessively greasy or heavy foods that may burden digestion, as Wu Ling Zhi already has a strong taste that can challenge a sensitive stomach.

Botanical Description

Physical characteristics and morphology of the Wu Ling Zhi source animal

Wu Ling Zhi is not derived from a plant but from an animal source. It is the dried feces of the complex-toothed flying squirrel (Trogopterus xanthipes Milne-Edwards), a medium-sized rodent endemic to China belonging to the family Petauristidae (flying squirrel family). The animal is slightly larger than a common squirrel, with a body length of 20–30 cm and weight of 300–500 g. It has a broad head, short snout, large round eyes, and prominent ears with tufts of black hair at the base. A gliding membrane stretches between its front and hind legs, allowing it to glide between cliffs and trees. Its fur is yellowish-brown with reddish tones on the back, grayish-white on the belly, and distinctively bright orange-yellow on the feet (hence the alternate name "orange-footed flying squirrel").

These squirrels inhabit rocky cliff faces and caves at elevations of 1,200–2,750 meters in mountainous regions with conifer and mixed forests. They are nocturnal, nesting in stone crevices on steep cliffs. Their diet consists primarily of Platycladus (Chinese arborvitae) leaves and seeds, along with pine bark and various tree seeds. The chemical composition of Wu Ling Zhi is directly influenced by this diet, as many of its active terpenoids, flavonoids, and lignans are metabolites of the foods the animals consume.

Sourcing & Harvesting

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

Harvesting season

Collected year-round, but primarily in spring and autumn. Spring-harvested material is considered higher quality.

Primary growing regions

The primary producing regions are Hebei, Shanxi, and Gansu provinces, which are considered the traditional terroir (道地药材) areas for Wu Ling Zhi. Additional production occurs in Shaanxi, Sichuan, Hubei, Yunnan, and Tibet. The herb is collected from the wild, gathered from cliff caves and rocky ledges where flying squirrels nest. Shanxi Province, particularly the Taihang Mountains and areas around Wutai Mountain, has historically been considered a premium source region.

Quality indicators

Wu Ling Zhi comes in two commercial grades based on form: Ling Zhi Kuai (灵脂块, block form) and Ling Zhi Mi (灵脂米, granular form). The block form (also called Tang Ling Zhi, "sugar Ling Zhi") consists of fecal pellets cemented together by dried urine into irregular lumps. High-quality blocks are black-brown to dark brown in colour, with a glossy surface that appears oily or resinous, and are free of sand, soil, or other impurities. Some blocks contain yellowish-brown resinous material between the pellets. The granular form consists of individual elongated pellets (0.5-1.2 cm long, 0.3-0.6 cm diameter) with a rough brownish-black surface. Good quality granules break easily and show a fibrous cross-section that is yellow-green to yellow in colour. The herb has a characteristic rank, musky odour and a bitter-salty taste. Block form is generally preferred for clinical use. Avoid material that is heavily contaminated with soil, overly crumbly, or has a foul rotten smell rather than the typical musky odour.

Classical Texts

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

《开宝本草》 (Kai Bao Ben Cao, Song Dynasty)

"主疗心腹冷气，小儿五疳，辟疫、治肠风，通利气脉，女子月闭。"

"Treats cold Qi in the heart and abdomen, the five childhood nutritional impairments (gan), dispels pestilence, treats intestinal wind, opens and frees the Qi vessels, and addresses menstrual cessation in women."

《本草纲目》 (Ben Cao Gang Mu, Li Shizhen)

"五灵脂，足厥阴肝经药也，气味俱厚，阴中之阴，故入血分。肝主血，故此药能治血病，散血和血而止诸痛。"

"Wu Ling Zhi is a medicine of the Foot Jue Yin Liver channel. Its Qi and flavour are both thick, Yin within Yin, and therefore it enters the Blood level. The Liver governs Blood, so this medicine can treat Blood diseases, scatter Blood, harmonize Blood, and stop all manner of pain."

《本草经疏》 (Ben Cao Jing Shu)

"五灵脂，其功长于破血行血，故凡瘀血停滞作痛，产后血晕，恶血冲心，少腹儿枕痛，留血经闭，瘀血心胃间作痛，血滞经脉，气不得行，攻刺疼痛等证，在所必用。"

"Wu Ling Zhi excels at breaking up and moving Blood. Therefore, whenever there is pain from stagnant Blood, postpartum blood dizziness, foul blood rushing to the heart, lower abdominal pillow pain, retained blood causing menstrual cessation, stasis pain between the heart and stomach, or Blood blockage in the channels preventing Qi movement with stabbing pain, this herb is indispensable."

《药品化义》 (Yao Pin Hua Yi)

"生用行血而不推荡，非若大黄之力迅而不守。炒用以理诸失血证，令血自归经而不妄行。"

"Used raw, it moves Blood without being overly forceful, unlike Da Huang (rhubarb) which is swift and unsettled. Dry-fried, it manages various bleeding conditions, causing Blood to return to the channels and cease its reckless flow."

Historical Context

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

Wu Ling Zhi (五灵脂), literally meaning "fat (or droppings) of the five spirits," was first recorded in the Kai Bao Ben Cao (开宝本草), a materia medica compiled during the Song Dynasty (around 973 CE). The original text identified it as the feces of the "cold-weather calling insect" (寒号虫, han hao chong). For centuries, there was debate about the identity of this creature. Some classical texts described it as a bird-like animal that called out in the cold, while others identified it as having "four feet and fleshy wings that cannot fly far." It was not until the 20th century that Chinese researchers from the Academy of Medical Sciences confirmed through field investigation that the source animal is the complex-toothed flying squirrel (Trogopterus xanthipes), a nocturnal gliding rodent that nests on cliff faces.

The herb's most famous clinical pairing is with Pu Huang (pollen of Typha) in the formula Shi Xiao San (失笑散, "Sudden Smile Powder"), recorded in the Tai Ping Hui Min He Ji Ju Fang (Song Dynasty). The formula's evocative name describes how patients in severe pain from Blood stasis suddenly smile with relief after taking it. Li Shizhen noted in the Ben Cao Gang Mu that this formula is effective not only for women's Blood pain but for "all heart, abdominal, flank, and lower abdominal pains in men, women, old, and young." The classical teaching that Wu Ling Zhi should be "used raw to move Blood, and dry-fried to stop bleeding" (生用行血，炒用止血) reflects one of TCM's most elegant examples of how processing transforms a single substance into two clinically opposite tools.

Modern Research

4 published studies investigating the pharmacological effects or clinical outcomes of Wu Ling Zhi

1

Antithrombotic flavonoids from the faeces of Trogopterus xanthipes (In vitro study, 2011)

Yang NY, Duan JA, Shang EX, Tian LJ. Planta Medica, 2010, 76(15), 1767-1769.

Chemical analysis of Trogopterus feces identified seven flavonoid compounds. Three kaempferol coumaroyl rhamnosides demonstrated significant antithrombin activity in laboratory assays, providing a pharmacological basis for the herb's traditional Blood-invigorating effects.

PubMed
2

Two new isopimarane diterpenes from the feces of Trogopterus xanthipes (Phytochemical study, 2010)

Yang NY, Tao WW, Zhu M, Duan JA, Jiang JG. Fitoterapia, 2010, 81(5), 381-384.

Researchers isolated two novel isopimarane diterpenes from the ethyl acetate extract of Wu Ling Zhi. The study confirmed that the herb's major chemical classes include triterpenoids, diterpenoids, and phenolic acids, and that it possesses antiplatelet aggregation and anti-inflammatory activities.

Link
3

Simultaneous Determination of Prostaglandin and Hormones in Excreta of Trogopterus xanthipes (Analytical study, 2020)

Liu H, Fan M, Fu X, Chen Y, Ye M, Guo H. Journal of Chromatographic Science, 2020, 58(6), 542-548.

This study performed qualitative and quantitative analysis of endogenous prostaglandins and hormones in Wu Ling Zhi using advanced chromatography. It identified 48 compounds in the squirrel's excreta, providing chemical evidence for the herb's traditional use in treating menstrual disorders.

PubMed
4

Fecal medicines used in traditional medical system of China: a systematic review (Review, 2019)

Xiao X, Zhou SH, Jiang N, et al. Chinese Medicine, 2019, 14, 40.

A comprehensive review of fecal medicines in Chinese medical traditions identified Wu Ling Zhi as the most representative and commonly used fecal medicine. The review described its active chemical constituents (terpenoids, flavonoids, lignans, and bile acids) as being closely related to the flying squirrel's diet of arborvitae leaves and pine bark.

Link

Research on individual TCM herbs is growing but still limited by Western clinical trial standards. These studies provide emerging evidence and should be considered alongside practitioner expertise.