What patterns does Chun Pi address?

Chun Pi addresses these TCM patterns of disharmony: Damp-Heat in the Lower Burner, Blood Heat, Spleen Qi Sinking.

What conditions is Chun Pi used for?

Chun Pi is commonly used for: White Vaginal Discharge, Chronic Diarrhea, Dysentery, Postmenstrual Bleeding, Bleeding Between Periods, Dark Blood In Stool, Hemorrhoids, Vaginal Itching, Intestinal Parasites. A TCM practitioner would consider this herb when these conditions arise from the specific patterns it addresses.

Herb Bark (皮 pí / 树皮 shù pí)

Chun Pi

Q: What are the TCM actions of Chun Pi?

The TCM actions of Chun Pi include: Clears Heat and dries Dampness, Astringes to Stop Vaginal Discharge, Astringes the Intestines and Stops Diarrhea, Stops Bleeding, Expels Parasites.

Ailanthus bark · 椿皮

Ailanthus altissima (Mill.) Swingle · Cortex Ailanthi

Also known as: Tree of Heaven Bark

Images shown are for educational purposes only

Ailanthus bark is a cooling, astringent herb used primarily for conditions involving excessive discharge or bleeding caused by Damp-Heat in the lower body. It is best known for treating chronic vaginal discharge, prolonged diarrhea or dysentery, and heavy menstrual or rectal bleeding. Because of its cold and drying nature, it is not suitable for people with weak, cold digestion.

Category Astringent / Stabilizing herbs (收涩药) Herbs that clear Heat and dry Dampness (清热燥湿药)

Therapeutic focus Women's Health Digestive Health Bleeding Disorders Vaginal Discharge Support

TCM Properties

Temperature

Cold

Taste

Bitter (苦 kǔ), Astringent (涩 sè)

Channels entered

Large Intestine, Liver, Stomach

Parts used

Bark (皮 pí / 树皮 shù pí)

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 Chun Pi does in the body, explained in both everyday and TCM terms

Therapeutic focus

In practical terms, Chun Pi is primarily used to support these areas of health:

Women's Health Digestive Health Bleeding Disorders Vaginal Discharge Support

TCM Actions

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

Clears Heat and dries Dampness Astringes to Stop Vaginal Discharge Astringes the Intestines and Stops Diarrhea Stops Bleeding Expels Parasites

How these actions work

'Clears Heat and dries Dampness' means Chūn Pí can reduce inflammatory, hot-type conditions that involve excess moisture in the body. Its bitter taste has a drying effect on pathological Dampness, and its cold temperature counteracts Heat. This is especially relevant in the lower body, where Damp-Heat can cause symptoms like foul-smelling vaginal discharge, bloody diarrhea, or dysentery.

'Astringes to stop vaginal discharge' refers to its ability to tighten and bind tissues that are "leaking" due to loss of control. In TCM, abnormal vaginal discharge (leukorrhea) often results from Damp-Heat pouring downward and weakening the Dai Mai (Belt Vessel). The astringent nature of Chūn Pí helps to firm up the body's holding capacity and reduce this discharge. This is one of its most recognized clinical uses and makes it a go-to herb for chronic leukorrhea with Heat signs.

'Astringes the intestines and stops diarrhea' means it can help contain and firm up loose bowels. This is particularly used for chronic, long-standing diarrhea or dysentery rather than acute conditions. The classical text Běn Cǎo Tōng Xuán notes that this herb works best when disease has persisted long enough that the intestines have become "slippery" and loose, and should not be used prematurely in acute illness, as premature binding could trap the pathogen inside.

'Stops bleeding' refers to its capacity to arrest various types of hemorrhage, especially those driven by Heat in the Blood. Because Chūn Pí is cold in nature, it is particularly suited for bleeding that is bright red or dark purplish, such as heavy menstrual bleeding (menorrhagia), uterine bleeding between periods (metrorrhagia), bloody stool, or hemorrhoidal bleeding.

'Kills parasites' is a secondary use. Taken internally, it has been used for roundworm-related abdominal pain, and applied externally as a wash, it treats scabies and fungal skin conditions.

Patterns Addressed

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

Why Chun Pi addresses this pattern

Chūn Pí's bitter taste dries Dampness and its cold temperature clears Heat, making it directly suited to Damp-Heat accumulating in the Lower Burner. This pattern often manifests as foul vaginal discharge or chronic dysentery with mucus and blood. By entering the Large Intestine and Liver channels, Chūn Pí targets the organs most commonly affected. Its astringent quality simultaneously addresses the loose, leaking quality of tissues damaged by prolonged Damp-Heat.

A practitioner would look for one or more of these signs

White Vaginal Discharge

Yellow or white foul-smelling vaginal discharge

Chronic Diarrhea

Chronic diarrhea with mucus or blood

Dysentery

Dysentery with tenesmus

Why Chun Pi addresses this pattern

Chūn Pí's cold nature directly counteracts Heat in the Blood that drives hemorrhage. When Heat enters the Blood level, it can force blood out of the vessels, leading to heavy menstrual bleeding, uterine bleeding, or bloody stool. The astringent quality of Chūn Pí helps contain the blood within the vessels while the cold temperature addresses the root Heat. It enters the Liver channel, which stores Blood and governs menstruation, making it particularly relevant for gynecological bleeding from Blood Heat.

A practitioner would look for one or more of these signs

Postmenstrual Bleeding

Heavy periods with dark purplish-red blood

Bleeding Between Periods

Uterine bleeding outside normal menstruation

Dark Blood In Stool

Blood in the stool from hemorrhoids or intestinal bleeding

Commonly Used For

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

Arises from: Damp-Heat in the Lower Burner

TCM Interpretation

In TCM, abnormal vaginal discharge (dai xia) is understood as a failure of the Dai Mai (Belt Vessel) to restrain downward flow, typically caused by Damp-Heat pouring into the Lower Burner. The Spleen normally transforms and transports fluids, but when it becomes burdened by Dampness, turbid fluids accumulate and descend. When Heat is also present, the discharge becomes yellow, thick, and foul-smelling. The Liver channel, which passes through the genital region, is also involved when Heat in the Liver combines with Dampness.

Why Chun Pi Helps

Chūn Pí addresses both sides of this condition: its bitter, cold nature clears Heat and dries Dampness in the Lower Burner, while its astringent quality firms up the Dai Mai's restraining function. It enters the Liver and Large Intestine channels, directly reaching the pelvic region where this pathology concentrates. Classical sources describe it as a primary herb for stopping vaginal discharge (止带之常用药物), and it is often combined with Huáng Bǎi (Phellodendron bark) to strengthen the Damp-Heat clearing effect.

Arises from: Damp-Heat in the Lower Burner Spleen Qi Sinking

TCM Interpretation

TCM views chronic diarrhea as involving either lingering Damp-Heat that irritates the intestines, or a weakened Spleen that can no longer hold and transform food properly. When diarrhea persists for weeks or months, the intestinal lining loses its integrity and becomes "slippery," allowing constant leakage. In the Damp-Heat type, there is often mucus, blood, and a burning sensation. In the deficiency type, the stool is watery and unformed with fatigue and poor appetite.

Why Chun Pi Helps

Chūn Pí works on chronic diarrhea through two mechanisms. First, its bitter and cold properties clear residual Damp-Heat that keeps the intestines inflamed. Second, and more distinctively, its astringent nature binds and firms the intestinal lining, addressing the "slippery" quality that allows chronic leakage. It enters the Large Intestine channel directly. Classical guidance from the Běn Cǎo Tōng Xuán emphasizes that this herb is best suited for long-standing cases where the intestines have become loose, not for new-onset diarrhea where the pathogen still needs to be expelled.

Also commonly used for

Dysentery

Chronic or acute bacterial dysentery

Bleeding Between Periods

Metrorrhagia and dysfunctional uterine bleeding

Dark Blood In Stool

Hemorrhoidal bleeding or intestinal blood in stool

Hemorrhoids

Bleeding hemorrhoids

Vaginal Itching

Trichomonas vaginitis (used internally and as external wash)

Intestinal Parasites

Roundworm infestation

Herb Properties

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

Temperature

Cold

Taste

Bitter (苦 kǔ), Astringent (涩 sè)

Channels Entered

Large Intestine Liver Stomach

Parts Used

Bark (皮 pí / 树皮 shù pí)

Dosage & Preparation

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

Standard dosage

6-9g

Maximum dosage

Up to 15g in decoction under practitioner supervision for acute dysentery or heavy vaginal discharge. Do not exceed this level, as higher doses commonly cause nausea and vomiting.

Dosage notes

Use 6-9g as the standard decoction dose for most indications including chronic diarrhea, vaginal discharge, and bleeding disorders. For acute bacterial dysentery, clinical reports have used up to 30g of fresh bark in a single day's decoction, divided into two doses, but this is not standard practice and requires close monitoring. Bran-fried Chun Pi (麸炒椿皮) has enhanced astringent properties and reduced potential for stomach irritation, making it preferable for chronic diarrhea and vaginal discharge. Charred Chun Pi (椿皮炭) is the preferred form for stopping bleeding (hemostatic use). For external use in treating skin conditions (scabies, dermatitis), the dosage is not strictly limited and the decoction is applied as a wash.

Preparation

No special decoction handling required. Decoct normally with other herbs. For enhanced astringency (chronic diarrhea, vaginal discharge), use the bran-fried form (麸炒椿皮). For hemostatic purposes (bleeding), use the charred form (椿皮炭). When using the raw herb in decoction for its mild clearing and draining properties, no processing is needed.

Processing Methods

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

Processing method

Bran-fried: wheat bran is scattered into a heated wok until smoking, then Chūn Pí strips are added and stir-fried until both sides are golden-yellow. The bran is sieved out and the herb is cooled. Ratio is approximately 10 parts bran to 100 parts herb.

How it changes properties

Bran-frying moderates the raw herb's cold nature and enhances its astringent, intestine-binding action. It also reduces the tendency of the raw herb to cause nausea. The thermal nature shifts from cold toward neutral-cool, making the processed form gentler on the Stomach.

When to use this form

Preferred for chronic diarrhea or dysentery in patients whose Spleen and Stomach are already somewhat weakened, where the full cold nature of the raw herb might be too harsh. Also the standard processed form used in most clinical prescriptions today.

Common Herb Pairs

These ingredients are traditionally combined with Chun Pi for enhanced therapeutic effect

Huang Qi 1:1

Chūn Pí and Huáng Bǎi together powerfully clear Damp-Heat from the Lower Burner. Huáng Bǎi strongly drains Damp-Heat downward and clears deficiency fire, while Chūn Pí adds an astringent, binding quality that stops discharge and leakage. Together they both clear the cause (Damp-Heat) and address the result (excessive discharge or bleeding).

When to use: Damp-Heat vaginal discharge (leukorrhea) that is yellow, foul-smelling, and persistent. Also for Damp-Heat dysentery.

Di Yu 1:1

Chūn Pí and Dì Yú both cool the Blood and stop bleeding, but through complementary mechanisms. Dì Yú is a strong Blood-cooling hemostatic that directly addresses bleeding in the lower body, while Chūn Pí adds astringent binding to firm up the intestinal lining. Together they provide both heat-clearing and tissue-tightening effects.

When to use: Bloody dysentery or chronic intestinal bleeding with Damp-Heat. Also hemorrhoidal bleeding.

He Zi 1:1

Hē Zǐ (Chebula fruit) is a powerful intestinal astringent that binds up the bowels. Combined with Chūn Pí, the astringent effect is doubled, providing strong containment for chronic, unrelenting diarrhea. Chūn Pí contributes its Damp-Heat clearing ability, while Hē Zǐ focuses purely on astringency.

When to use: Chronic diarrhea or dysentery that has persisted long enough that the intestines are "slippery" and loose. Used in the classical formula Hē Lí Lè Wán from the Pí Wèi Lùn.

Bai Shao Bái Sháo 15g : Chūn Pí 12g

Bái Sháo nourishes Blood and preserves Yin while softening the Liver, complementing Chūn Pí's astringent hemostatic action. While Chūn Pí stops bleeding through cold and astringency, Bái Sháo addresses the underlying Blood or Yin Deficiency that often accompanies chronic blood loss. This pairing treats both the symptom (bleeding) and the consequence (Blood Deficiency).

When to use: Heavy menstrual bleeding or metrorrhagia due to Blood Heat with underlying Yin or Blood Deficiency. Core pairing in Gù Jīng Wán.

Key Formulas

These well-known formulas feature Chun Pi in a prominent role

Gu Jing Wan 固经丸 Assistant

Gù Jīng Wán (Stabilize the Menses Pill) from the Dān Xī Xīn Fǎ is the most iconic formula association for Chūn Pí. It treats heavy menstrual bleeding or metrorrhagia due to Yin Deficiency with Blood Heat. Chūn Pí serves as assistant, using its bitter, cold astringency to hold the Blood and prevent further loss while the other herbs (Guī Bǎn, Bái Sháo, Huáng Qín, Huáng Bǎi) nourish Yin and clear Heat. This formula perfectly showcases Chūn Pí's dual ability to stop bleeding and clear Heat.

Comparable Ingredients

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

Chun Pi vs Huang Qi

Both are bitter, cold herbs that clear Damp-Heat from the Lower Burner. However, Huáng Bǎi is stronger at clearing deficiency fire and draining Kidney fire, and does not have significant astringent properties. Chūn Pí, by contrast, combines Damp-Heat clearing with strong astringency, making it the better choice when there is active discharge or bleeding that needs to be contained. For pure Damp-Heat without leakage, Huáng Bǎi suffices; when discharge or chronic diarrhea is the presenting complaint, Chūn Pí is preferred.

Chun Pi vs Qin Pi

Both Chūn Pí and Qín Pí (Ash bark) clear Heat, dry Dampness, and treat dysentery. Qín Pí also benefits the eyes and is used for eye disorders with Heat, an action Chūn Pí does not share. Chūn Pí has a much stronger astringent action for stopping vaginal discharge and uterine bleeding, so for gynecological conditions with Damp-Heat, Chūn Pí is the clear choice. For dysentery with concurrent eye inflammation, Qín Pí may be preferred.

Chun Pi vs Bai Ji

Both herbs stop bleeding, but through very different mechanisms. Bái Jí (Bletilla rhizome) is an astringent hemostatic for the upper body, particularly for Lung and Stomach bleeding (hemoptysis, stomach ulcer bleeding). Chūn Pí targets bleeding in the lower body, including uterine and intestinal hemorrhage, and adds Damp-Heat clearing that Bái Jí does not provide. The choice depends on the location of bleeding: upper body favors Bái Jí, lower body and gynecological conditions favor Chūn Pí.

Identity & Adulterants

Related species and common adulterations to be aware of when sourcing Chun Pi

The most important distinction is between the bark of the stinking cedar (臭椿, Ailanthus altissima, Simaroubaceae family) and the fragrant cedar (香椿, Toona sinensis, Meliaceae family). Historically, both have been used under the umbrella name 'Chun Pi' or 'Chun Bai Pi,' and commercial markets often mix the two. The modern Chinese Pharmacopoeia defines Chun Pi specifically as the Ailanthus altissima bark. To distinguish: Ailanthus bark (stinking cedar) is grayish-yellow to yellowish-brown, has a faint rancid oily odor (especially when broken), and tastes very bitter. Toona bark (fragrant cedar) is reddish-brown, has a mild pleasant aroma (slightly fragrant when chewed), and tastes bland. Toona bark cross-sections are distinctly fibrous and can be peeled in layers, while Ailanthus bark has a characteristic granular outer and fibrous inner cross-section. In some regional traditions (Sichuan, Shaanxi, Hubei, Guizhou), the Toona bark is still used or the two are used interchangeably.

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

Toxicity Classification

Classical Chinese pharmacopoeia toxicity rating for Chun Pi

Non-toxic

The Chinese Pharmacopoeia classifies Chun Pi as non-toxic, though some historical sources (notably the Ben Cao Jing Shu citing the Shen Nong Ben Cao Jing) record it as having slight toxicity (有毒). The bark contains quassinoid compounds (ailanthone, ailanthinone, shinjulactones) and beta-carboline alkaloid derivatives. At standard decoction doses (6 to 9g), it is generally well tolerated. Excessive dosage can cause nausea, vomiting, and gastrointestinal discomfort. Modern pharmacological research has noted that ailanthone, the primary bioactive quassinoid, has a toxicity profile that can cause gastrointestinal damage at high concentrations, though this is primarily relevant to isolated compound research rather than traditional bark decoctions at standard doses.

Contraindications

Situations where Chun Pi should not be used or requires extra caution

Caution

Spleen and Stomach deficiency-cold (脾胃虚寒): Chun Pi is bitter, astringent, and cold in nature. It can further damage the Spleen and Stomach Yang in those with underlying cold-type digestive weakness, worsening diarrhea or abdominal discomfort.

Caution

Vaginal discharge or uterine bleeding due to Kidney Yin deficiency (肾家真阴虚): The herb's strongly drying nature can further deplete Yin fluids. The classical text Ben Cao Jing Shu explicitly warns against its use in this pattern, noting it is 'uselessly drying' (徒燥) in such cases.

Caution

Acute dysentery or diarrhea where pathogenic accumulation has not yet been cleared (滞下积气未尽): Because Chun Pi is astringent, using it too early in an acute condition can trap the pathogen inside the body. The Ben Cao Tong Xuan warns that premature use of this astringent herb in new illness may 'transform into other diseases and become chronic.'

Caution

Excessive dosage can cause nausea and vomiting. The herb should be used within the standard dosage range, and patients with sensitive stomachs should be monitored.

Special Populations

Important considerations for pregnancy, breastfeeding, and pediatric use

Pregnancy

Chun Pi should be used with caution during pregnancy. Its bitter, cold, and drying nature can deplete fluids and potentially affect fetal nourishment. Additionally, the quassinoid compounds it contains (particularly ailanthone) have shown cytotoxic properties in laboratory studies, and their effects on fetal development have not been adequately studied. While it is not listed among the most strictly prohibited herbs in pregnancy, it is best avoided unless specifically prescribed by an experienced practitioner for a clearly defined condition.

Breastfeeding

No specific safety data exists for the use of Chun Pi during breastfeeding. Given its bitter and cold properties and the presence of quassinoid compounds (ailanthone, ailanthinone) and alkaloid derivatives, there is a theoretical concern about transfer of these bioactive substances into breast milk. It is prudent to avoid use during breastfeeding unless specifically prescribed by a qualified practitioner, and only at standard doses for a limited duration.

Children

Chun Pi may be used in pediatric practice at appropriately reduced doses for conditions such as chronic diarrhea or intestinal parasites, which are among its traditional indications. Dosage should be reduced proportionally based on age and body weight, typically one-third to one-half of the adult dose for children over 5 years old. Its bitter taste may cause difficulty with compliance. It should not be used in infants or very young children without specific practitioner guidance, given its drying and cold properties which can easily overwhelm a child's delicate digestive system.

Drug Interactions

If you are taking pharmaceutical medications, be aware of these potential interactions with Chun Pi

No well-documented drug interactions have been established through clinical studies. However, based on the known pharmacology of its active compounds, the following theoretical interactions warrant caution:

Anticoagulant and antiplatelet medications: Chun Pi has hemostatic (blood-stopping) properties. It may theoretically counteract the effects of blood-thinning drugs such as warfarin, heparin, or aspirin, reducing their therapeutic efficacy.
Antidiarrheal medications: The herb's astringent, intestine-binding properties may have additive effects with pharmaceutical antidiarrheals (e.g., loperamide), potentially leading to excessive constipation.
Cytotoxic or chemotherapy agents: Ailanthone and other quassinoids have demonstrated anticancer activity in laboratory studies. There is a theoretical risk of unpredictable interactions with conventional chemotherapy drugs, potentially affecting drug metabolism or toxicity profiles.

Dietary Advice

Foods and dietary considerations when taking Chun Pi

While taking Chun Pi, avoid cold, raw, and greasy foods that may further burden the Spleen and generate Dampness, as this would work against the herb's therapeutic purpose. Since Chun Pi is cold in nature, pairing it with warm, easily digested foods (cooked grains, soups, lightly cooked vegetables) helps protect the digestive system. Avoid alcohol, which generates Damp-Heat and may irritate the gastrointestinal tract. For those taking it for vaginal discharge or dysentery, spicy and stimulating foods should also be minimized.

Botanical Description

Physical characteristics and morphology of the Chun Pi source plant

Ailanthus altissima (Mill.) Swingle, commonly known as the Tree of Heaven or stinking tree (臭椿, chòu chūn), is a fast-growing deciduous tree in the Simaroubaceae (quassia) family that can reach 18 to 25 meters in height. The bark is smooth and pale gray on young trees, developing fissures as the tree matures. Its leaves are large, alternate, and pinnately compound, typically 50 to 100 cm long with 11 to 25 leaflets, giving the tree a tropical appearance. Each leaflet has a distinctive notched, glandular base that distinguishes it from similar-looking sumac species. The tree is mostly dioecious (separate male and female trees), producing small yellow-green flowers in large clusters in early summer. Male flowers have a notably unpleasant odor, and indeed all parts of the tree emit a characteristic acrid, rancid smell. Female trees produce reddish-brown winged fruits (samaras) in autumn.

The Tree of Heaven is native to China and Taiwan and is extremely adaptable, tolerating poor soils, pollution, and urban conditions. It reproduces prolifically by both seed and root suckers and has become an aggressive invasive species across much of Europe, North America, and other temperate regions. The medicinal part used in Chinese medicine is the dried root bark or trunk bark (the inner bark after the rough outer cork layer is removed).

Sourcing & Harvesting

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

Harvesting season

Can be harvested year-round. The bark is stripped from roots or trunk at any season, though spring and summer (when sap flow is active) allow easier peeling.

Primary growing regions

Chun Pi is produced throughout most of China. Major production areas include Shandong, Liaoning, Henan, and Anhui provinces. The tree grows wild or is cultivated along roadsides, mountain slopes, and village edges throughout northern, eastern, and southwestern China. It is distributed in virtually all provinces except the far northeast (Heilongjiang, Jilin) and far west/northwest (Xinjiang, Qinghai, Gansu). There is no single strongly defined 'terroir' region (道地药材) for this herb, as the tree grows abundantly and opportunistically across a wide range.

Quality indicators

Good quality root bark (the preferred medicinal part) appears as flat or irregularly rolled pieces, 0.3 to 1 cm thick. The outer surface should be grayish-yellow or yellowish-brown with prominent, longitudinally elongated lenticels (pore-like bumps). When the rough outer cork is removed, the surface appears pale yellowish-white. The inner surface should be pale yellow, relatively smooth, and densely dotted with small spindle-shaped pores or spots. The texture should be hard and brittle, with the cross-section showing a granular outer layer and a fibrous inner layer. The smell should be faint (with a slight oily, fishy-rancid odor when broken, characteristic of the stinking cedar), and the taste distinctly bitter. Avoid pieces that are moldy, insect-damaged, or excessively dark. Thick pieces with clean white inner surfaces are considered best.

Classical Texts

Key passages from the classical Chinese medical texts that describe Chun Pi and its therapeutic uses

《本草通玄》 (Ben Cao Tong Xuan)

Original: 「椿皮，专以固摄为用，故泻痢肠风，遗浊崩带者，并主之。然必病久而滑，始为相宜，若新病蚤服，强勉固涩，必变他症而成痼疾矣。凡用刮去粗皮，生用则能通利，酸醋炙即能固涩。」

Translation: Chun Pi is used specifically for its binding and astringent functions. It treats chronic diarrhea, dysentery, intestinal wind, turbid discharges, flooding (uterine bleeding), and vaginal discharge. However, it is only appropriate when the illness is long-standing and slippery (chronic looseness). If used prematurely in a new illness, forcing astringency, it will inevitably transform into other diseases and become chronic and intractable. When using it, scrape off the rough outer bark. Used raw it has a mildly opening effect; roasted with vinegar it becomes strongly astringent.

《本草纲目》 (Ben Cao Gang Mu) by Li Shizhen

Original: 「椿皮色赤而香，樗皮色白而臭，多服微利人。盖椿皮入血分而性涩，樗皮入气分而性利，不可不辨。」

Translation: Chun Pi (fragrant cedar bark) is reddish in color and aromatic, while Shu Pi (stinking cedar bark) is white and malodorous. Taken in excess, the latter mildly loosens the bowels. Chun Pi enters the Blood aspect and is astringent in nature, while Shu Pi enters the Qi aspect and has a freeing nature. One must distinguish between them.

《本草经疏》 (Ben Cao Jing Shu)

Original: 「藏器又主杀蛔虫蛊毒下血及赤白久痢；《日华子》治肠风泻血……皆取其苦能燥湿，寒能除热，涩能收敛之功耳。」

Translation: [Various classical sources record that] it kills roundworms and gu-toxin, stops bleeding, and treats chronic red and white dysentery. The Ri Hua Zi (materia medica) treats intestinal wind with bloody stools. All of these applications rely on its bitter taste to dry Dampness, its cold nature to clear Heat, and its astringent quality to bind and contain.

Historical Context

The history and evolution of Chun Pi's use in Chinese medicine over the centuries

Chun Pi has a complex botanical and nomenclature history. The name 'Chun Pi' (椿皮) has historically been applied to the bark of two related but taxonomically distinct trees: the fragrant cedar or Toona sinensis (香椿, Meliaceae family) and the stinking cedar or Ailanthus altissima (臭椿, Simaroubaceae family). Classical materia medica texts from the Tang dynasty onward frequently discussed the two together. In the Xin Xiu Ben Cao (新修本草, Tang dynasty), it was already noted that the two trees resemble each other in form but differ in that one has dense, fragrant wood while the other has loose, foul-smelling wood. Li Shizhen in the Ben Cao Gang Mu carefully distinguished the two, stating that Chun Pi (the fragrant variety) enters the Blood aspect and is astringent, while Shu Pi (the stinking variety) enters the Qi aspect and has a freeing quality. In modern pharmacy, the Chinese Pharmacopoeia defines Chun Pi as the bark of Ailanthus altissima (the stinking variety), while the fragrant cedar bark is used only in certain regional traditions.

The genus name Ailanthus derives from an Ambonese word meaning 'heaven-tree' or 'tree reaching for the sky.' The tree was brought to Europe from China in the 1750s and to America in 1784, initially prized as an ornamental and for feeding silkworm caterpillars. Chinese miners during the California Gold Rush also brought seeds with them, likely for its medicinal and cultural value. It is famously the tree featured in the novel A Tree Grows in Brooklyn, symbolizing resilience in harsh conditions.

Modern Research

4 published studies investigating the pharmacological effects or clinical outcomes of Chun Pi

Comprehensive review: Traditional uses, phytochemistry, and pharmacology of Ailanthus altissima bark (2021)

Journal of Ethnopharmacology, 2021, Volume 275, Article 114132

A systematic review covering 60 years of research (1960-2020) on the bark of Ailanthus altissima. The review found that the bark possesses significant potential for treating cancer and gastrointestinal inflammation, documenting its rich phytochemistry including quassinoids, alkaloids, terpenoids, and phenylpropanoids, and summarizing pharmacological activities including anti-tumor, anti-inflammatory, antimicrobial, and antiparasitic effects.

PubMed

Anticancer properties and mechanism of action of the quassinoid ailanthone (Review, 2020)

Boussahel S, et al. Pharmacological Research, 2020, Volume 158, Article 104891

This review examined the anticancer mechanisms of ailanthone, a key quassinoid from Ailanthus altissima. Ailanthone showed significant antitumor effects against multiple cancer cell lines in the laboratory and in animal models of liver cancer, non-small cell lung cancer, and castration-resistant prostate cancer. It works through activating DNA damage responses, inhibiting the Hsp90 co-chaperone p23, and modulating several microRNAs. However, the review notes that toxicity (particularly gastrointestinal damage) may limit clinical development unless proper formulations are developed.

PubMed

Antiplasmodial activity of extracts and quassinoids from Ailanthus altissima seedlings (In vitro study, 2003)

Okunade AL, et al. Phytochemistry, 2003, Volume 65, Pages 1017-1032

This laboratory study isolated quassinoids from Ailanthus altissima and tested them against the malaria parasite Plasmodium falciparum. Two quassinoids, ailanthone and 6-alpha-tigloyloxychaparrinone, showed activity against both chloroquine-resistant and chloroquine-sensitive strains. Ailanthone also demonstrated low toxicity to normal kidney cells, suggesting selectivity for the parasite.

PubMed

Anti-inflammatory constituents from stem barks of Ailanthus altissima: LPS-induced nitric oxide inhibition (2015)

Kim HM, et al. Bioorganic & Medicinal Chemistry Letters, 2015, Volume 25, Pages 1017-1021

Researchers isolated 15 compounds from Ailanthus altissima stem bark, including three new canthinone-type alkaloids and four quassinoids. These compounds were screened for anti-inflammatory activity by measuring their ability to inhibit nitric oxide production (a marker of inflammation) in laboratory immune cells, supporting the traditional use of the bark for inflammatory conditions.

PubMed

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.