Herb Root (根 gēn)

Long Dan Cao

Chinese gentian root · 龙胆草

Gentiana scabra Bge. · Radix et Rhizoma Gentianae

Also known as: Long Dan (龙胆), Dan Cao (胆草)

Long Dan Cao (Chinese gentian root) plant

Images shown are for educational purposes only

Long Dan Cao (Chinese gentian root) is one of the most powerfully bitter and cold herbs in Chinese medicine, used to drain excess Heat from the Liver and Gallbladder and to clear Damp-Heat from the lower body. It is commonly used for conditions like red, painful eyes, headaches with irritability, rib-side pain, bitter taste in the mouth, and urogenital inflammation with itching or discharge. Because of its very cold nature, it is typically used short-term and is not suitable for people with weak digestion or cold constitutions.

Category Herbs that clear Heat and dry Dampness (清热燥湿药)
Therapeutic focus Liver Health Eye Health and Vision Urinary Health Skin Health

TCM Properties

Temperature

Cold

Taste

Bitter (苦 kǔ)

Channels entered

Liver, Gallbladder

Parts used

Root (根 gēn)

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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 Long Dan Cao does in the body, explained in both everyday and TCM terms

Therapeutic focus

In practical terms, Long Dan Cao is primarily used to support these areas of health:

Liver Health Eye Health and Vision Urinary Health Skin Health

TCM Actions

In TCM terminology, these are the specific therapeutic actions that Long Dan Cao performs to restore balance in the body:

Clears Heat and dries Dampness Drains Liver and Gallbladder Fire Clears Damp-Heat from the Lower Burner Arrests Convulsions

How these actions work

'Clears Heat and dries Dampness' means Long Dan Cao eliminates conditions where Heat and excessive moisture combine in the body, particularly along the Liver and Gallbladder channels. This is one of the most intensely bitter herbs in the Chinese pharmacopoeia, and bitterness in TCM is the taste that dries Dampness and sends things downward. It is especially useful for jaundice caused by Damp-Heat, vaginal discharge that is yellow or foul-smelling, genital itching and swelling, and eczema with itching and weeping.

'Drains Liver and Gallbladder Fire' means this herb powerfully quenches excess Heat in the Liver and Gallbladder systems. When Liver Fire flares upward, it can cause red, painful eyes, headaches (especially at the temples and top of the head), a bitter taste in the mouth, ringing in the ears or sudden hearing loss, pain along the ribs, and irritability. Long Dan Cao's cold, sinking nature directly opposes and drains this upward-flaring Fire. It is considered the primary herb for excess Liver and Gallbladder Fire conditions.

'Clears Damp-Heat from the Lower Burner' refers to this herb's ability to resolve conditions involving Heat and Dampness in the pelvic and urogenital areas. This includes painful or burning urination, genital swelling, itching, abnormal discharge, and scrotal eczema. Because the Liver channel runs through the genital region, Long Dan Cao's strong affinity for the Liver channel makes it especially effective here.

'Calms convulsions' refers to its use for high fever with convulsions or spasms, particularly in children. In TCM, extreme Liver Heat can generate internal Wind, which manifests as tremors, seizures, or muscle spasms. By powerfully draining Liver Fire, Long Dan Cao removes the root cause driving these convulsions.

Patterns Addressed

In TCM, symptoms cluster into recognizable patterns of disharmony. Long Dan Cao is used to help correct these specific patterns.

Why Long Dan Cao addresses this pattern

Long Dan Cao is the premier herb for Liver Fire blazing upward. Its intensely bitter and cold nature directly opposes the hot, rising nature of Liver Fire. It enters the Liver and Gallbladder channels where it powerfully drains excess Heat, counteracting the upward flaring that causes head and eye symptoms. The bitter taste forces Qi downward, while the cold nature extinguishes the Fire. Classical sources describe it as 'greatly bitter, greatly cold' and the primary medicinal for Liver and Gallbladder excess Fire.

A practitioner would look for one or more of these signs

Headaches

Throbbing headache, especially at the temples or vertex

Red Eyes

Red, swollen, painful eyes

Tinnitus

Sudden onset tinnitus or hearing loss

Irritability

Irritability and restlessness

Bitter Taste In The Mouth

Persistent bitter taste in the mouth

Commonly Used For

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

Arises from: Liver Fire Blazing

TCM Interpretation

In TCM, the eyes are closely connected to the Liver. The saying 'the Liver opens to the eyes' means that the health of the Liver system directly affects vision and eye comfort. When Liver Fire blazes upward, the Heat rises along the Liver channel to the eyes, causing redness, swelling, pain, and a burning or gritty sensation. The condition may be accompanied by headache, irritability, and a bitter taste in the mouth, all pointing to excess Heat in the Liver and Gallbladder.

Why Long Dan Cao Helps

Long Dan Cao directly drains the Liver Fire that is causing the eye inflammation. Its intensely bitter and cold nature powerfully clears Heat from the Liver channel, and since this channel connects directly to the eye system, the herb targets the root cause of the redness and pain. Modern research has shown that gentian root extracts have demonstrated anti-inflammatory and antimicrobial properties, supporting its traditional use for eye infections. Historically, gentian decoctions were even used as eyewash solutions for acute conjunctivitis.

Also commonly used for

Hepatitis

Acute hepatitis, particularly with jaundice

Cholecystitis

Acute cholecystitis with rib-side pain and bitter mouth

Hypertension

Hypertension with dizziness, headache, and tinnitus from Liver Fire

Eczema

Eczema, especially in the genital or inguinal region

Otitis Media

Acute middle ear infection

Vaginitis

Vaginitis with yellow discharge and itching

Pelvic Inflammatory Disease

Acute pelvic inflammatory disease

Hyperthyroidism

Hyperthyroidism with Liver Fire signs

Prostatitis

Acute prostatitis

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)

Channels Entered

Liver Gallbladder

Parts Used

Root (根 gēn)

Dosage & Preparation

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

Standard dosage

3–6g

Maximum dosage

Up to 9–12g in severe Liver Fire patterns, under practitioner supervision. Doses above 6g should be used only for short courses.

Dosage notes

The standard dosage is 3-6g in decoction. Lower doses (3g) are adequate for mild Liver Fire symptoms such as eye redness or bitter taste. Higher doses (6-9g) may be used for more severe Damp-Heat conditions like acute jaundice or intense urogenital inflammation, but should not be continued long-term. Because the herb is so intensely bitter and cold, it is commonly paired with Gan Cao (licorice) to soften the bitter taste and protect the Stomach. Wine-processed Long Dan Cao (jiu chao) has a slightly moderated cold nature and is preferred when the target is upper-body symptoms like headache, eye redness, and ear problems, as the wine processing helps direct the herb upward.

Preparation

No special decoction handling required. Decoct normally with other herbs. When using wine-processed Long Dan Cao (for upper-body symptoms), specify this to the herbalist. During preparation, avoid prolonged soaking in water, as the high sugar content of the roots can cause active glycosides to dissolve and be lost. Brief rinsing and moistening is preferred over extended soaking.

Processing Methods

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

Processing method

The dried root is stir-fried with rice wine (huang jiu) until the wine is absorbed and the herb appears slightly darker. Some traditions specify wine-washing or wine-soaking followed by drying.

How it changes properties

Wine processing moderates Long Dan Cao's extremely bitter and cold nature, reducing its tendency to damage the Stomach. More importantly, wine's ascending and dispersing nature helps guide the herb's actions upward and outward, enhancing its ability to treat symptoms in the upper body such as headache, red eyes, ear problems, and temporal pain. The core channel affinity (Liver, Gallbladder) remains unchanged, but the directional tendency shifts from purely descending to also reaching upward.

When to use this form

Preferred when the main symptoms are in the upper body, such as Liver Fire flaring upward causing headache, red swollen eyes, ear pain, and rib-side pain. The raw form is better for Damp-Heat conditions in the Lower Burner (genital itching, vaginal discharge, jaundice, urinary problems), where the herb's natural downward-draining action is desired.

Common Herb Pairs

These ingredients are traditionally combined with Long Dan Cao for enhanced therapeutic effect

Yin Chen
Yin Chen Long Dan Cao 6g : Yin Chen Hao 15-30g

Long Dan Cao dries Dampness and clears Heat from the Liver and Gallbladder, while Yin Chen Hao (Artemisia capillaris) specifically promotes bile flow, resolves jaundice, and has a diuretic effect. Together, they powerfully clear Damp-Heat from the hepatobiliary system and resolve yellowing of the skin and eyes.

When to use: Damp-Heat jaundice, such as acute hepatitis or cholecystitis with yellow discoloration of the skin, dark urine, and a greasy yellow tongue coating.

Huang Qin
Huang Qin 1:1.5 (Long Dan Cao 6g : Huang Qin 9g)

Both herbs are bitter and cold and clear Heat, but Long Dan Cao specifically drains Liver and Gallbladder Fire while Huang Qin (Scutellaria) clears Heat more broadly from the Upper and Middle Burners. Together they create a comprehensive Fire-clearing effect across the Liver, Gallbladder, and Lung systems, amplifying each other's ability to resolve inflammation.

When to use: Liver and Gallbladder Fire with associated upper body Heat signs such as red eyes, headache, bitter mouth, and rib-side pain. This pairing forms the core Heat-clearing axis of Long Dan Xie Gan Tang.

Zhi Zi
Zhi Zi 1:1.5 (Long Dan Cao 6g : Zhi Zi 9g)

Long Dan Cao drains Fire specifically from the Liver and Gallbladder, while Zhi Zi (Gardenia fruit) clears Heat from the Heart and all three Burners and guides Fire downward through the urine. Together they provide a powerful dual-pathway clearance of excess Fire from both the Liver system and the whole body.

When to use: Liver Fire with marked irritability, restlessness, insomnia, dark scanty urine, and a red tongue. The combination is especially useful when Fire symptoms affect both the Liver (red eyes, rib pain) and the Heart (agitation, insomnia).

Chai Hu
Chai Hu 1:1 (Long Dan Cao 6g : Chai Hu 6g)

Long Dan Cao drains Liver Fire with its heavy, descending nature, while Chai Hu (Bupleurum) lifts and spreads Liver Qi, preventing the bitter cold from suppressing the Liver's natural need to flow freely. Chai Hu also acts as a channel-guiding herb, directing the formula's actions into the Liver and Gallbladder. This pairing balances draining with spreading, preventing over-suppression of Liver function.

When to use: Liver and Gallbladder Fire or Damp-Heat where there is both excess Heat and Qi stagnation. The classic context is Long Dan Xie Gan Tang, where this pairing ensures that clearing Fire does not create new stagnation.

Huang Qi
Huang Qi 1:1 (Long Dan Cao 6g : Huang Bai 6-9g)

Both herbs clear Damp-Heat from the Lower Burner, but Long Dan Cao focuses on the Liver and Gallbladder channels while Huang Bai (Phellodendron bark) targets the Kidneys and Bladder. Together they provide broad-spectrum Damp-Heat clearance across the entire lower body, covering both urogenital and renal systems.

When to use: Lower Burner Damp-Heat with genital itching, abnormal vaginal discharge, scrotal eczema, or urinary difficulty where both the Liver and Kidney channel systems are involved.

Key Formulas

These well-known formulas feature Long Dan Cao in a prominent role

Long Dan Xie Gan Tang 龙胆泻肝汤 King

This is the defining formula for Long Dan Cao and the most widely known formula it appears in. Long Dan Cao serves as the King herb, showcasing both of its core actions simultaneously: draining Liver and Gallbladder excess Fire (treating headache, red eyes, ear problems, bitter mouth) and clearing Damp-Heat from the Lower Burner (treating genital itching, abnormal discharge, painful urination). The formula perfectly illustrates the herb's dual capacity.

Xie Qing Wan 泻青丸 King

From the Xiao Er Yao Zheng Zhi Jue (Key to Patterns and Treatment in Children's Diseases), this formula uses Long Dan Cao as the King herb to directly drain Liver Fire causing convulsions, red eyes, and restlessness in children. It showcases the herb's ability to calm convulsions by eliminating their root cause (extreme Liver Heat), and combines it with Wind-dispersing herbs to address the Fire-generates-Wind pathomechanism.

Dang Gui Long Hui Wan 当归龙荟丸 Deputy

This formula assembles a team of intensely bitter and cold herbs to powerfully purge Liver Fire in severe excess patterns with delirium, constipation, and dark urine. Long Dan Cao serves as Deputy alongside herbs like Huang Lian, Huang Bai, and Huang Qin, representing its use in extreme Liver Fire scenarios where the strongest possible Fire-draining approach is required.

Comparable Ingredients

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

Huang Qin
Long Dan Cao vs Huang Qin

Both are bitter and cold Heat-clearing herbs, but they target different organ systems. Long Dan Cao specifically drains Liver and Gallbladder Fire and clears Damp-Heat from the Lower Burner. Huang Qin has a broader scope, entering the Lung, Gallbladder, Stomach, and Large Intestine channels, and is more commonly used for Lung Heat (cough with yellow phlegm) and Upper Burner Heat. Choose Long Dan Cao for clear Liver Fire patterns with red eyes, rib pain, and bitter mouth; choose Huang Qin for Lung Heat or broader upper body Heat patterns.

Huang Qi
Long Dan Cao vs Huang Qi

Both clear Damp-Heat from the Lower Burner, but they work through different channel systems. Long Dan Cao enters the Liver and Gallbladder and excels at draining Liver Fire alongside clearing Damp-Heat. Huang Bai enters the Kidneys and Bladder and is better for Kidney-related Damp-Heat and also clears deficiency Heat (empty Fire from Yin Deficiency). Choose Long Dan Cao when the pattern centers on the Liver (irritability, red eyes, rib pain); choose Huang Bai when Kidney or Bladder Damp-Heat predominates, or when there is deficiency Heat with night sweats.

Qin Pi
Long Dan Cao vs Qin Pi

Both enter the Liver and Gallbladder channels and clear Heat, but their secondary actions differ significantly. Long Dan Cao is purely draining and drying, making it the stronger choice for Liver Fire and Damp-Heat. Qin Pi (Fraxinus bark) combines Heat-clearing with astringency, which makes it more suitable for dysentery and diarrhea from Damp-Heat in the Large Intestine, as well as eye conditions. Choose Long Dan Cao for direct Liver Fire with upward-flaring symptoms; choose Qin Pi when the Damp-Heat involves the bowels or when astringency is needed.

Common Substitutes & Adulterants

Related species and common adulterations to be aware of when sourcing Long Dan Cao

Long Dan Cao is sometimes adulterated with Niu Xi (Achyranthes) root segments, which are cut to a similar size but lack the characteristic extreme bitterness. As one market report noted, adulterated Long Dan Cao may actually taste sweet rather than bitter, which is a clear red flag. The authentic herb should be overwhelmingly bitter on tasting. The four official Pharmacopoeia species should be distinguished from each other: the three northeastern species (G. scabra, G. manshurica, G. triflora) known as "Guan Long Dan" and the Yunnan species (G. rigescens) known as "Jian Long Dan" or "Dian Long Dan." While both are legitimate, they differ in morphology and chemical profile. Jian Long Dan has shorter roots (6-15 cm), a more brittle, horn-like texture, and an easily peeling surface. Dong Bei Long Dan (Gentiana manshurica) is sometimes used as a substitute in Shandong province. Always verify provenance and confirm the characteristic extreme bitterness.

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

Toxicity Classification

Classical Chinese pharmacopoeia toxicity rating for Long Dan Cao

Non-toxic

Long Dan Cao is classified as non-toxic in the Chinese Pharmacopoeia (2020 edition) and has no toxicity marking. Animal studies on gentiopicroside, its primary bioactive compound, indicate low toxicity. However, its extreme bitterness and cold nature mean that excessive doses or prolonged use can injure the Spleen and Stomach, leading to poor appetite, nausea, loose stools, and general digestive weakness. Classical sources warn that overuse can deplete Qi and Blood. At the standard dosage of 3-6g in decoction, the herb has a well-established safety profile.

Contraindications

Situations where Long Dan Cao should not be used or requires extra caution

Caution

Spleen and Stomach deficiency cold (脾胃虚寒): Long Dan Cao is extremely bitter and cold. In people with weak digestion, loose stools, poor appetite, or cold-type abdominal pain, it can severely damage the Spleen and Stomach Yang, worsening digestive symptoms.

Caution

Absence of excess Heat or Damp-Heat: This herb is only appropriate for true excess (shi) patterns of Liver-Gallbladder Fire or Damp-Heat in the lower burner. Using it when there is no genuine Heat or dampness will needlessly injure the body's Qi and Blood.

Caution

Yin deficiency without excess Fire: In patterns of Yin deficiency with deficiency Heat (as opposed to excess Liver Fire), Long Dan Cao's intensely cold and draining nature can further deplete Yin fluids and damage the constitution. Bai Shao (white peony) is more appropriate for restraining deficiency Heat of the Liver.

Caution

Prolonged or excessive use: Classical sources warn that overuse damages the stomach's generative Qi and may paradoxically promote Fire, similar to the rebound effect seen with long-term Huang Lian use. Treatment should stop once the condition improves (zhong bing ji zhi, 中病即止).

Caution

Empty stomach administration: The Ben Cao Jing Shu warns that taking Long Dan Cao on an empty stomach can cause urinary incontinence due to its extremely bitter, downward-draining nature.

Special Populations

Important considerations for pregnancy, breastfeeding, and pediatric use

Pregnancy

Use with caution during pregnancy. Long Dan Cao's intensely bitter and cold nature, combined with its strong downward-draining action, could potentially destabilize the fetus by injuring Spleen and Stomach Qi (which support fetal nourishment) or by its general downward-moving tendency. There is no specific evidence of teratogenicity, but classical teaching advises caution with strongly cold and bitter herbs during pregnancy. Use only under practitioner guidance when clearly indicated.

Breastfeeding

Caution is advised during breastfeeding. Long Dan Cao's extremely bitter and cold properties may theoretically pass through breast milk and affect the nursing infant's delicate digestive system, potentially causing loose stools or poor feeding. There is limited direct evidence on breast milk transfer. If clinically necessary for a breastfeeding mother (e.g., for acute Liver Fire), use at the lowest effective dose for the shortest duration, under practitioner supervision.

Children

Long Dan Cao has a long classical history of use in pediatric conditions, particularly childhood fright-Wind (jing feng) with convulsions caused by Liver Heat. It appears in classical pediatric formulas such as Xie Qing Wan from Qian Yi's Xiao Er Yao Zheng Zhi Jue. However, its extremely bitter and cold nature makes it potentially harsh on a child's immature digestive system. Dosages should be significantly reduced compared to adult doses (typically 1-2g for young children), and the duration of use should be kept short. It should only be used under practitioner guidance and is not suitable for children with weak digestion.

Drug Interactions

If you are taking pharmaceutical medications, be aware of these potential interactions with Long Dan Cao

No well-documented serious drug interactions have been established in clinical studies. However, based on its known pharmacological properties, the following theoretical interactions should be considered:

  • Sedative and CNS-depressant medications: Long Dan Cao and its constituent gentianine have demonstrated sedative effects in animal studies. Concurrent use with benzodiazepines, barbiturates, or other sedatives may theoretically potentiate sedation.
  • Hepatically metabolised drugs: Gentiopicroside has hepatoprotective and choleretic effects that may alter hepatic drug metabolism. Patients taking medications with narrow therapeutic windows that are liver-metabolised should use Long Dan Cao with caution.
  • Hypoglycaemic agents: Gentiopicroside has been shown to improve insulin resistance and glucose homeostasis in animal models, which could theoretically enhance the effects of oral hypoglycaemic drugs or insulin.
  • Antihypertensive medications: The herb has demonstrated blood pressure-lowering effects, which could add to the effects of antihypertensive drugs.

These interactions are theoretical and based on preclinical data. Patients on prescription medications should consult their healthcare provider before using Long Dan Cao.

Dietary Advice

Foods and dietary considerations when taking Long Dan Cao

While taking Long Dan Cao, avoid greasy, fried, and heavily spiced foods, as these can generate internal Heat and Dampness, counteracting the herb's therapeutic purpose. Avoid alcohol for the same reason. Because the herb is strongly cold, also avoid excessive consumption of raw, cold foods (ice cream, cold drinks, raw salads) which could compound the herb's tendency to chill the Stomach. Light, bland, easily digestible foods are best during treatment.

Botanical Description

Physical characteristics and morphology of the Long Dan Cao source plant

Gentiana scabra Bunge (and related official species G. manshurica, G. triflora, G. rigescens) is a perennial herbaceous plant in the Gentianaceae family, growing 30–60 cm tall. The whole plant is green, sometimes tinged with purple. The rhizome is short, giving rise to clusters of numerous slender, yellowish-white roots with transverse wrinkles. Stems are erect, single, and somewhat rough-textured.

Leaves are opposite, with the lower leaves small and scale-like. The middle and upper leaves are ovate to ovate-lanceolate, 2.5–8 cm long, with 3–5 prominent veins and rough margins that clasp the stem at the base. Flowers are borne in clusters of 2–5 at the stem apex and upper leaf axils. The corolla is a striking deep blue to blue-purple, bell-shaped with five lobes. Flowering occurs from August to September, with fruits ripening by autumn.

The plant favours cool, moist mountain habitats at various elevations. It grows wild on sunny mountain slopes, in sparse forests, shrublands, and grasslands. It is cold-hardy (tolerating temperatures to about -25°C) and prefers humus-rich, well-drained, slightly acidic to neutral soils. Cultivated plants require 2–4 years before the roots reach harvestable size.

Sourcing & Harvesting

Where Long Dan Cao is sourced, when it's harvested or collected, and how to assess quality

Harvesting season

Spring and autumn, with autumn harvest (around mid to late October) yielding the best quality.

Primary growing regions

The three northern species (Gentiana scabra, G. manshurica, G. triflora), collectively called "Guan Long Dan" (关龙胆), are primarily produced in the northeast provinces of China: Heilongjiang, Jilin, and Liaoning, as well as parts of Inner Mongolia. These northeastern origins are considered the traditional dao di (道地) source for the highest quality herb. The fourth official species, Gentiana rigescens, known as "Jian Long Dan" (坚龙胆) or "Dian Long Dan" (滇龙胆), is produced in Yunnan province in southwest China. Wild gentian also occurs in Shandong, Guizhou, Anhui, and other provinces, as well as in Russia, Korea, and Japan.

Quality indicators

Good quality Long Dan Cao (Guan Long Dan / northeastern variety) has a short, irregularly shaped rhizome with numerous long, slender roots attached. The roots should be 10-20 cm long and 2-4 mm in diameter. The surface colour should be pale yellow to yellowish-brown, with prominent fine horizontal wrinkles on the upper portion and longitudinal wrinkles below. The texture should be brittle when dry but becomes soft and pliable when it absorbs moisture. On cross-section, the interior should be yellowish-brown with a visible ring of yellow-white dots (wood portion) arranged in a circle, and a clear pith. The aroma should be faint, and the taste extremely bitter. Avoid material that tastes sweet (may indicate adulteration with Niu Xi roots or other substitutes), has a mushy or rotten interior, or shows signs of insect damage.

Classical Texts

Key passages from the classical Chinese medical texts that describe Long Dan Cao and its therapeutic uses

Shen Nong Ben Cao Jing (《神农本草经》)

Original: 主骨间寒热，惊痫邪气，续绝伤，定五脏，杀蛊毒。

Translation: "It governs alternating cold and Heat lodged in the bones, fright epilepsy and pathogenic Qi, mends severed injuries, stabilises the five Zang organs, and kills parasitic toxins."

Ben Cao Gang Mu (《本草纲目》) — Li Shizhen

Original: 相火寄在肝胆，有泻无补，故龙胆之益肝胆之气，正以其能泻肝胆之邪热也。但大苦大寒，过服恐伤胃中生发之气，反助火邪。

Translation: "Ministerial Fire lodges in the Liver and Gallbladder, where there is draining but no tonification. Thus Long Dan Cao benefits the Qi of the Liver and Gallbladder precisely because it can drain their pathological Heat. However, being extremely bitter and cold, excessive use may injure the Stomach's generative Qi, and paradoxically promote Fire."

Ben Cao Zheng (《本草正》)

Original: 龙胆草，乃足厥阴、少阳之正药，大能泻火，但引以佐使，则诸火皆治。凡肝肾有余之火，皆其所宜。

Translation: "Long Dan Cao is the principal herb for the Foot Jueyin (Liver) and Shaoyang (Gallbladder) channels. It powerfully drains Fire, and when guided by assistant herbs, it can treat all types of Fire. It is appropriate for any excess Fire of the Liver and Kidneys."

Yi Xue Zhong Zhong Can Xi Lu (《医学衷中参西录》) — Zhang Xichun

Original: 龙胆草，味苦微酸，为胃家正药。其苦也，能降胃气，坚胃质；其酸也，能补益胃中酸汁，消化饮食……其泻肝胆实热之力，数倍于芍药。

Translation: "Long Dan Cao, bitter with a slight sour flavour, is a principal herb for the Stomach. Its bitterness descends Stomach Qi and strengthens Stomach substance; its sourness supplements Stomach acid and aids digestion... Its power to drain Liver and Gallbladder excess Heat is many times greater than that of Shao Yao (peony)."

Historical Context

The history and evolution of Long Dan Cao's use in Chinese medicine over the centuries

Long Dan Cao has been used in Chinese medicine for over two thousand years. It was first recorded in the Shen Nong Ben Cao Jing (Divine Farmer's Classic of Materia Medica), China's oldest materia medica, where it was classified as a middle-grade herb. Its earliest recorded name was "Ling You" (陵游). The name "Long Dan" (龙胆, literally "dragon's gallbladder") derives from the observation that its leaves resemble those of the Long Kui plant (dragon-sunberry), and its taste is as intensely bitter as bile. It ranks as the second most bitter substance in the Chinese materia medica, exceeded only by Ma Qian Zi (Strychnos nux-vomica) and surpassing even the famously bitter Huang Lian (Coptis).

The herb's clinical profile evolved significantly over the centuries. The Shen Nong Ben Cao Jing focused on its ability to treat bone-level Heat and childhood fright conditions. By the Song dynasty, it had become the chief ingredient of Long Dan Xie Gan Tang (Gentian Liver-Draining Decoction), one of the most important formulas for Liver-Gallbladder excess Heat and Damp-Heat. The Qing dynasty physician Zhang Xichun offered a distinctive interpretation, noting a subtle sour quality and describing it as a "principal herb for the Stomach" that promotes gastric secretions. Modern practitioners continue to use it primarily for Liver-Gallbladder Fire patterns and lower-burner Damp-Heat conditions, while pharmacological research has confirmed its hepatoprotective and choleretic properties.

Modern Research

4 published studies investigating the pharmacological effects or clinical outcomes of Long Dan Cao

1

Gentiopicroside: An Updated Review of Its Pharmacological Activities and Mechanisms (Review, 2024)

Aktar MA et al. Chemistry and Biodiversity. 2024; e202400874.

This review examined the key bioactive compound of Long Dan Cao, gentiopicroside (GPS). The authors found that GPS can protect the liver from alcohol and toxin-induced injury, shows antitumor activity by inducing cancer cell death, and may improve diabetes by supporting healthy blood sugar and reducing inflammation. Toxicity studies indicated that GPS has low toxicity overall.

Link
2

Gentiopicroside: An Insight into Its Pharmacological Significance and Future Perspectives (Review, 2023)

Antoniadi L, Bartnik M, Angelis A, Wawruszak A, Halabalaki M, Kukula-Koch W, Skaltsounis LA. Cells. 2023 Dec 29;13(1):70.

A comprehensive review of gentiopicroside's biological effects, covering anti-inflammatory, hepatoprotective, antitumor, antimicrobial, and bone-protective activities. The authors concluded that GPS plays a meaningful role in multiple metabolic pathways and holds promise for treating digestive disorders, malignancies, neurological conditions, and inflammatory diseases.

Link
3

Regulatory Mechanisms of Gentiopicroside on Human Diseases: A Brief Review (Review, 2024)

Liu B, Pang F, Bi H, Guo D. Naunyn-Schmiedeberg's Archives of Pharmacology. 2024;397(2):725-750.

This review synthesized evidence for gentiopicroside's hepatoprotective, anti-inflammatory, antifibrotic, antioxidant, analgesic, antitumor, and immunomodulatory properties. The authors noted that optimizing its bioavailability and understanding its drug interactions remain important areas for future research.

Link
4

The Chemical Structure, Pharmacological Activity, and Clinical Progress of Gentianae Radix et Rhizoma (Review, 2025)

Frontiers in Pharmacology. 2025; 10.3389/fphar.2025.1656493.

A broad review covering 172 compounds identified from Gentiana species (2004-2024). The authors found that iridoids like gentiopicroside and swertiamarin are the key bioactive agents, with demonstrated anti-inflammatory effects via NF-kB and MAPK pathway suppression, hepatoprotective activity via Nrf2 activation, and antitumor effects through induction of cancer cell death.

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.