Ingredient Mineral (矿物 kuàng wù)

Long Gu

Dragon Bone (fossilised mammal bone) · 龙骨

N/A (fossilized bones of ancient large mammals including Elephantidae, Rhinocerotidae, Cervidae, Bovidae, Equidae spp.) · Fossilia Ossis Mastodi

Also known as: Wu Hua Long Gu (五花龙骨)

Long Gu (Dragon Bone (fossilised mammal bone)) plant

Images shown are for educational purposes only

Dragon bone is a fossilized mineral substance used in Chinese medicine to calm the mind and settle anxiety, restlessness, and insomnia. It is also used to help manage dizziness and irritability caused by Liver imbalances, and its astringent nature helps reduce excessive sweating, chronic diarrhea, and other conditions involving fluid loss.

Category Substances that anchor and calm the Spirit (重镇安神药)
Therapeutic focus Sleep and Anxiety Support Emotional Wellbeing Blood Pressure Support Excessive Sweating

TCM Properties

Temperature

Neutral

Taste

Sweet (甘 gān), Astringent (涩 sè)

Channels entered

Heart, Liver, Kidneys

Parts used

Mineral (矿物 kuàng 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 Long Gu does in the body, explained in both everyday and TCM terms

Therapeutic focus

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

Sleep and Anxiety Support Emotional Wellbeing Blood Pressure Support Excessive Sweating

TCM Actions

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

Calms the Spirit and Settles Fright Calms the Liver and anchors floating Yang Secures Essence and Stops Leakage Astringes to Stop Sweating Promotes Tissue Regeneration and Heals Sores

How these actions work

'Settles fright and calms the Spirit' means that Long Gu has a heavy, weighty quality that anchors an unsettled mind. In TCM, the Heart houses the Spirit (Shen), and when the Spirit is disturbed, a person may experience anxiety, restlessness, palpitations, insomnia, or even manic episodes. Long Gu's mineral heaviness is thought to 'weigh down' the Spirit so it can rest peacefully in the Heart. This is why it is one of the most commonly used substances for insomnia, anxiety, and nervous agitation.

'Calms the Liver and anchors floating Yang' refers to Long Gu's ability to suppress rising Liver Yang. When Liver Yin is deficient, Yang rises upward unchecked, producing dizziness, headaches, ringing in the ears, irritability, a flushed face, and a sensation of heat in the head. Long Gu sinks this rising Yang back downward. It is almost always paired with Mu Li (oyster shell) for this purpose, and the pair forms the core of many formulas for high blood pressure and stroke prevention.

'Astringes and prevents leakage of fluids' describes Long Gu's ability to tighten and contain substances that the body is losing. Because of its astringent taste, it can help with a wide range of 'leakage' conditions: spontaneous sweating or night sweats, seminal emissions, frequent urination or incontinence, chronic diarrhea, vaginal discharge, and uterine bleeding. The calcined (heat-processed) form is stronger for this purpose.

'Generates flesh and closes sores' applies only to external (topical) use. When ground into powder and applied to non-healing ulcers, weeping eczema, or chronic wounds, calcined Long Gu helps dry the area and promote tissue repair.

Patterns Addressed

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

Why Long Gu addresses this pattern

When the Heart Spirit (Shen) is unsettled due to emotional shock, overwork, blood deficiency, or heat harassing the Heart, the result is anxiety, palpitations, insomnia, and restlessness. Long Gu enters the Heart channel and its heavy, mineral nature physically anchors the Spirit, calming it back into the Heart. Its sweet taste gently supports without being overstimulating, making it suitable for both excess and deficiency presentations of Spirit disturbance. Zhang Xichun noted in the Yi Xue Zhong Zhong Can Xi Lu that Long Gu's sticky, astringent quality allows it to 'collect the original Qi and calm the Spirit.'

A practitioner would look for one or more of these signs

Insomnia

Difficulty falling or staying asleep

Palpitations

Heart palpitations with anxiety

Anxiety

Restlessness and fearfulness

Dream-Disturbed Sleep

Excessive dreaming or nightmares

Commonly Used For

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

Arises from: Heart Spirit Disturbance

TCM Interpretation

In TCM, healthy sleep depends on the Spirit (Shen) being properly housed in the Heart. When the Spirit is agitated by emotional stress, fright, blood deficiency failing to nourish the Heart, or heat flaring upward, it cannot settle at night, resulting in insomnia. The Heart and Liver are the two organs most closely involved: the Heart houses the Spirit, while the Liver stores the 'ethereal soul' (Hun) that governs dream activity. When both are disturbed, a person may experience both difficulty falling asleep and vivid, disturbing dreams.

Why Long Gu Helps

Long Gu directly addresses insomnia by anchoring the unsettled Spirit. Its heavy, mineral quality physically weighs the Spirit down into the Heart so it can rest. Unlike sedating herbs that simply dampen mental activity, Long Gu works by stabilizing and containing, which is why classical sources describe it as able to 'collect the original Qi and calm the Spirit.' Its neutral temperature means it does not introduce additional heat or cold, making it safe for a wide range of insomnia presentations. It is almost always combined with Mu Li (oyster shell) for enhanced effect, and this pairing forms the backbone of many classical sleep formulas.

Also commonly used for

Palpitations

Heart palpitations with or without anxiety

Epilepsy

Seizure disorders, historically used in classical formulas

Night Sweats

Deficiency-type sweating during sleep

Excessive Sweating

Spontaneous sweating from Qi deficiency

Spermatorrhea

Involuntary seminal emissions

Chronic Diarrhea

Long-standing diarrhea from Spleen or Kidney weakness

Bleeding

Abnormal uterine bleeding or heavy periods

Eczema

Topical use of calcined form for weeping lesions

Dizziness

Vertigo from Liver Yang rising

Ingredient Properties

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

Temperature

Neutral

Taste

Sweet (甘 gān), Astringent (涩 sè)

Channels Entered

Heart Liver Kidneys

Parts Used

Mineral (矿物 kuàng wù)

Dosage & Preparation

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

Standard dosage

15-30g

Maximum dosage

Up to 30-45g in severe cases of Qi collapse, profuse sweating, or heavy uterine bleeding, under practitioner supervision. Must be decocted first (先煎) for at least 20-30 minutes.

Dosage notes

Use lower doses (15-20g) for calming the spirit and anchoring Liver Yang. Use higher doses (20-30g) for heavy astringent action in cases of severe sweating, uterine bleeding, or chronic diarrhea. Use raw (Sheng Long Gu) for calming the spirit and subduing Liver Yang. Use calcined (Duan Long Gu) for stronger astringent action in treating fluid leakage, non-healing sores, and generating flesh. Zhang Xichun advised using Long Gu raw in almost all situations, reserving the calcined form only for emergencies such as life-threatening uterine hemorrhage. For pills and powders, a much smaller dose of 1-3g per serving is standard.

Preparation

Long Gu is a dense mineral substance and must be decocted first (先煎, xian jian). Crush or break into small pieces, then add to water and boil for 20-30 minutes before adding the other herbs in the prescription. When used as powder for external application or in pills and powders for internal use, it should be finely ground and ideally water-levigated (水飞) to produce an ultra-fine powder that will not irritate the gastrointestinal tract. Wrap in cloth (包煎) if using fine powder in decoction to prevent cloudiness.

Processing Methods

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

Processing method

The raw Long Gu pieces are placed in a smokeless fire or suitable container and calcined at high heat (武火) until they glow red throughout. They are then removed, cooled, and crushed or ground into powder.

How it changes properties

Calcination shifts the temperature from neutral to more neutral/mild and significantly strengthens the astringent action. The taste becomes more astringent with less emphasis on the sweet quality. The calcined form loses much of its Spirit-calming and Yang-anchoring potency but gains a much stronger ability to astringe fluids, stop bleeding, and promote wound healing when applied topically.

When to use this form

Use calcined Long Gu when the primary goal is astringent and stopping leakage: heavy sweating, severe uterine bleeding (崩漏), chronic diarrhea that has not responded to other treatment, seminal emissions, or topically for chronic non-healing ulcers and weeping eczema. Zhang Xichun noted he used the raw form for almost all purposes, reserving the calcined form only for emergencies like severe uterine hemorrhage or threatened miscarriage where maximum astringent power was needed immediately.

Common Ingredient Pairs

These ingredients are traditionally combined with Long Gu for enhanced therapeutic effect

Mu Li Ke
Mu Li Ke 1:1 (commonly 15-30g each)

The most classical and essential herb pair for Long Gu. Both substances are heavy minerals that anchor and calm, but they work through complementary mechanisms. Long Gu is sweet and astringent, excelling at calming the Spirit and preventing fluid leakage. Mu Li is salty and astringent, better at nourishing Yin, softening hardness, and dissipating nodules. Together they powerfully anchor floating Yang, calm the Spirit, and astringe fluids, covering both the Yin-nourishing and Yang-anchoring aspects that neither does alone.

When to use: Used in virtually every clinical situation where Long Gu is indicated: insomnia, anxiety, palpitations, Liver Yang rising with dizziness and headache, spontaneous sweating, night sweats, seminal emissions, vaginal discharge, uterine bleeding, and chronic diarrhea. This pair appears in Chai Hu Jia Long Gu Mu Li Tang, Gui Zhi Jia Long Gu Mu Li Tang, Zhen Gan Xi Feng Tang, and Gu Chong Tang.

Zhen Zhu Mu
Zhen Zhu Mu 1:1 (commonly 15-30g each)

Both are heavy substances entering the Heart and Liver channels. Zhen Zhu Mu (mother of pearl) is salty and cool, with the ability to clear Heart heat and calm Liver fire in addition to calming the Spirit. Long Gu adds stronger fright-settling and astringent actions. Together they enhance both Spirit-calming and Liver-Yang-anchoring effects, with the combined effect especially strong for calming the Spirit.

When to use: When Heart Spirit disturbance features prominent heat signs such as irritability, red eyes, or a red tongue tip, or when Liver Yang rising is accompanied by Liver fire. This pair is stronger at clearing heat than the Long Gu and Mu Li pair.

Lian Xu
Lian Xu 2:1 (Long Gu 15-20g : Lian Xu 6-10g)

Long Gu astringes and prevents fluid leakage broadly, while Lian Xu (lotus stamen) specifically consolidates Kidney essence. Together they create a focused astringent effect on the Kidney's ability to store essence, significantly strengthening the effect on seminal emissions and spermatorrhea.

When to use: Kidney deficiency with involuntary seminal emissions, premature ejaculation, or vaginal discharge. Often combined with additional Kidney-consolidating herbs like Qian Shi and Yi Zhi Ren.

Huang Qi
Huang Qi Huang Qi 15-30g : Long Gu 15-30g

Huang Qi tonifies Spleen Qi and consolidates the exterior to stop sweating, while Long Gu astringes fluid leakage. Together they address the root (Qi deficiency) and the branch (sweating) simultaneously, creating a much stronger anti-perspiration effect than either alone.

When to use: Spontaneous sweating from Qi deficiency, where the body's surface defense (Wei Qi) is too weak to hold fluids in. The person typically catches colds easily and sweats with minimal exertion.

Key Formulas

These well-known formulas feature Long Gu in a prominent role

Chai Hu Jia Long Gu Mu Li Tang 柴胡加龙骨牡蛎汤 Deputy

This Shang Han Lun formula (Article 107) is one of the most famous formulas containing Long Gu. It treats a complex presentation of chest fullness, agitation, fright, delirium, and heaviness of the body after improper treatment of a febrile illness. Long Gu works alongside Mu Li to provide the heavy, Spirit-settling anchor that calms the disturbed Shen, showcasing its core action of settling fright and calming the Spirit in a complex excess pattern.

Gui Zhi Jia Long Gu Mu Li Tang 桂枝加龙骨牡蛎汤 Deputy

From the Jin Gui Yao Lue, this formula treats deficiency taxation (xu lao) with seminal emissions, dream-disturbed sleep, and palpitations caused by disharmony between Yin and Yang. Long Gu and Mu Li are added to the base Gui Zhi Tang to astringe essence and anchor the Spirit, perfectly demonstrating Long Gu's dual capacity to both calm the mind and prevent fluid/essence leakage in a deficiency context.

Zhen Gan Xi Feng Tang 镇肝熄风汤 Deputy

From Zhang Xichun's Yi Xue Zhong Zhong Can Xi Lu, this is the representative formula for Liver Yang rising causing internal Wind (manifesting as hypertension, dizziness, or stroke). Long Gu serves as Deputy alongside Mu Li to anchor floating Yang and calm internal Wind, showcasing its Liver-calming and Yang-anchoring actions in a serious clinical context.

Gu Chong Tang 固冲汤 Assistant

Also from Zhang Xichun's Yi Xue Zhong Zhong Can Xi Lu, this formula treats uterine bleeding (崩漏) from Spleen Qi deficiency with failure to control the Chong vessel. Calcined Long Gu appears alongside calcined Mu Li as astringent Assistants to stem the bleeding, demonstrating its processed form's stronger astringent and hemostatic capacity.

Comparable Ingredients

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

Mu Li Ke
Long Gu vs Mu Li Ke

The closest comparable substance and most frequent pairing partner. Both anchor Yang and calm the Spirit, but Mu Li (oyster shell) is salty and cool, giving it additional abilities that Long Gu lacks: it nourishes Yin, softens hardness, and dissipates nodules (useful for goiter and masses). Long Gu is sweeter and more astringent, making it stronger at settling fright, stopping fluid leakage, and astringing. As the classical text Ben Cao Qiu Zhen noted, Mu Li enters the Kidney with its salty taste and softens, while Long Gu enters the Liver with its sweet taste and astringes. In practice they are almost always used together.

Long Chi
Long Gu vs Long Chi

Long Chi (dragon teeth, Dens Draconis) comes from the same fossil source but uses the teeth rather than the bones. Both calm the Spirit and anchor Yang, but Long Chi is cooler and specializes in settling fright and calming the Spirit for severe anxiety, palpitations, and seizures. It lacks Long Gu's astringent, fluid-containing action, so it is not used for sweating, emissions, or diarrhea. Choose Long Chi when Spirit-calming is the sole priority, Long Gu when astringent action is also needed.

Zhu Sha
Long Gu vs Zhu Sha

Both are heavy mineral substances classified as Spirit-calming herbs. Zhu Sha (cinnabar) is cold and enters the Heart, making it more powerful at clearing Heart fire and sedating the Spirit in acute, severe presentations like high fever with delirium or mania. However, Zhu Sha contains mercury and is toxic with prolonged use, limiting its clinical application. Long Gu is non-toxic, has astringent properties that Zhu Sha lacks, and is safe for longer-term use. Long Gu is the safer everyday choice, while Zhu Sha is reserved for acute, severe cases under strict supervision.

Therapeutic Substitutes

Legitimate clinical replacements when Long Gu is unavailable, restricted, or contraindicated

Mu Li

Mu Li Ke
Mu Li Ke 牡蛎壳
Oyster shell

Covers: Covers Lóng Gǔ's core actions of calming the mind, anchoring rising Liver Yang, and astringing to prevent fluid loss (spontaneous sweating, night sweats, seminal emission, vaginal discharge). Classical texts including 《注解伤寒论》 and 《本草求真》 explicitly identify Mǔ Lì as similar in therapeutic effect to Lóng Gǔ, with comparable chemical composition and overlapping actions in both animal models and clinical use.

Does not cover: Mǔ Lì enters different channels (Liver, Gallbladder, Kidney — versus Lóng Gǔ's Heart, Liver, Kidney) and its salty, cold nature gives it a stronger softening-of-hardness and phlegm-resolving action that Lóng Gǔ does not share. Conversely, Lóng Gǔ's astringent action for consolidating Qi and stopping leakage is generally considered stronger, particularly for external sore-healing (calcined form). In patterns with significant Heat, Mǔ Lì's cold nature is more appropriate; in neutral or deficiency-cold presentations, this difference matters clinically.

Use when: When Lóng Gǔ is unavailable or difficult to source at good quality, or when the clinical picture includes Liver Yang rising with signs of Heat, phlegm nodules, or swelling — situations where Mǔ Lì's additional softening action is also beneficial. Widely used as a practical substitution in many modern Chinese clinical settings.

Long Chi

Long Chi
Long Chi 龙齿
Dragon Tooth Fossil

Covers: Covers Lóng Gǔ's shen-calming and Liver Yang-anchoring functions. Lóng Chǐ (fossilized mammal teeth) shares the same origin type, production areas, and TCM classification as Lóng Gǔ, and is considered especially effective for palpitations, anxiety, insomnia, dream-disturbed sleep, and fright — arguably stronger than Lóng Gǔ for these particular indications.

Does not cover: Lóng Chǐ completely lacks Lóng Gǔ's astringent, consolidating action. It cannot substitute for Lóng Gǔ's use in treating spontaneous sweating, night sweats, seminal emission, urinary incontinence, uterine bleeding, or vaginal discharge, nor for its topical use on non-healing sores and ulcers (calcined Lóng Gǔ). It is also slightly cooler in thermal nature than the neutral Lóng Gǔ.

Use when: When the primary clinical goal is calming the mind and anchoring Liver Yang — especially in patterns featuring strong fright, palpitations, and agitation — and the astringent/consolidating aspect of Lóng Gǔ is not required. Also appropriate when Lóng Gǔ of good quality is unavailable but Lóng Chǐ can be sourced.

Identity & Adulterants

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

Mu Li (牡蛎, Oyster Shell) is the most commonly used clinical substitute, having similar calming, anchoring, and astringent functions, though with different channel tropism and additional ability to soften hardness and nourish Yin. Research has shown calcined pig bone (煅猪骨) to be the closest mineral-composition match to calcined Long Gu and is being investigated as a modern substitute. Dangerous adulterants include fluoride-rich dinosaur fossils (which have a very different mineral profile and may contain harmful levels of fluoride), processed modern cattle or pig bones passed off as fossil, and plain calcium carbonate mineral. Authentic Long Gu can be distinguished by its characteristic porous microstructure, strong hygroscopic quality (tongue-adhering test), and the presence of trace elements zinc and strontium. Long Chi (龙齿, Dragon Teeth) is a related but distinct product from fossilized teeth, which is stronger for calming the spirit but lacks the astringent/binding functions of Long Gu.

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

Toxicity Classification

Classical Chinese pharmacopoeia toxicity rating for Long Gu

Non-toxic

Long Gu is classified as non-toxic. The Ming Yi Bie Lu records it as non-toxic (无毒), though the Yao Xing Lun noted "slightly toxic" (有小毒). Its main components are calcium carbonate, calcium phosphate (carbonated hydroxyapatite), and trace minerals including iron, potassium, zinc, strontium, manganese, and copper. No toxic organic compounds are present. The primary safety concern is not inherent toxicity but adulteration: modern market analysis has found dangerous substitutes including fluoride-rich dinosaur fossils and processed modern animal bones that do not match the trace element profile of authentic material. Proper sourcing from reputable suppliers is essential. A secondary concern noted in classical texts is that insufficiently processed (not water-levigated) Long Gu may irritate the intestines and stomach over time, potentially causing internal Heat. This is why some classical processing methods recommend water-flying (水飞) the powder.

Contraindications

Situations where Long Gu should not be used or requires extra caution

Caution

Damp-Heat conditions: Long Gu's astringent nature can trap Damp-Heat internally, potentially worsening symptoms such as burning urination (dysuria), sticky stools, or yellow discharge. It should not be used in patterns where Damp-Heat has not been cleared.

Caution

Active exterior (externally contracted) conditions: Because Long Gu is strongly astringent and inward-drawing, using it while a pathogen is still on the exterior can trap the pathogen inside the body, preventing proper resolution of the illness.

Caution

Excess Heat with Fire blazing upward: In cases where spermatorrhea or night sweats are caused by vigorous Fire rather than true deficiency, Long Gu's astringent nature may worsen the condition. As the Ben Cao Feng Yuan warns, misuse in these cases can lead to painful, scanty, reddish urination and worsened loss of essence.

Classical Incompatibilities

Traditional Chinese pharmacological incompatibilities — herbs or substances to avoid combining with Long Gu

Long Gu does not appear on the classical Eighteen Incompatibilities (十八反) or Nineteen Mutual Fears (十九畏) lists. Some traditional sources caution against combining Long Gu with Shi Gao (石膏, Gypsum) and Gan Qi (干漆, dry lacquer), but these are not part of the standard incompatibility lists and lack strong classical consensus.

Special Populations

Important considerations for pregnancy, breastfeeding, and pediatric use

Pregnancy

Generally considered safe at standard doses during pregnancy. Long Gu is not listed among pregnancy-prohibited or pregnancy-caution herbs in standard Chinese Materia Medica texts. In fact, classical sources such as the Ri Hua Zi Ben Cao specifically mention its use for threatened miscarriage (漏胎) and stopping uterine bleeding during pregnancy. However, its strongly astringent nature means it should be used with care and only under practitioner guidance, as inappropriate use (for example, in the presence of Damp-Heat or unresolved pathogenic factors) could trap harmful conditions internally. Always consult a qualified practitioner before use during pregnancy.

Breastfeeding

No specific contraindications for use during breastfeeding are documented in classical or modern sources. Long Gu is a mineral substance composed primarily of calcium salts and trace minerals, and its components are not known to transfer through breast milk in harmful concentrations. It may be used at standard doses under practitioner supervision. However, as with all medicinal substances during breastfeeding, use should be guided by an appropriately qualified practitioner.

Children

Long Gu has been used in pediatric practice since antiquity and is specifically mentioned in the Shen Nong Ben Cao Jing for treating childhood fright epilepsy (小儿热气惊痫). It is considered safe for children at appropriately reduced dosages (typically one-third to one-half of adult dose depending on the child's age and weight). It is commonly used in pediatric formulas for night crying, restlessness, fright, and bedwetting. For infants and toddlers, external application of powdered Long Gu is used for umbilical conditions and non-healing sores. Internal use should always be under practitioner supervision.

Drug Interactions

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

Cardiac glycosides (Digoxin): Long Gu's high calcium content may enhance the effects and toxicity of cardiac glycosides. Concurrent use requires monitoring of drug blood levels.

Quinidine and related antiarrhythmics: Long Gu is alkaline in nature and may reduce renal excretion of quinidine, potentially raising blood levels to toxic range. Close monitoring is recommended if co-administered.

Tetracycline antibiotics and Isoniazid: The calcium ions in Long Gu can form chelation complexes with these drugs, reducing their absorption and therapeutic efficacy. Separate administration by at least 2 hours.

Phosphate-containing and sulfate-containing drugs (e.g. chloroquine phosphate, codeine phosphate, ferrous sulfate): Long Gu's calcium can form insoluble precipitates with these medications, reducing their bioavailability.

Corticosteroids (Prednisolone): Co-administration may form poorly soluble compounds, significantly reducing the bioavailability of the steroid.

Vitamin C: Some sources note that Long Gu may accelerate oxidation of Vitamin C, reducing its effectiveness.

Dietary Advice

Foods and dietary considerations when taking Long Gu

When taking Long Gu for calming the spirit and settling anxiety, avoid stimulating foods and drinks such as strong coffee, alcohol, and heavily spiced dishes, which may counteract its sedating effects. When using Long Gu for its astringent properties (treating sweating, diarrhea, or discharge), support its action by favouring warm, easily digestible, cooked foods and avoiding cold, raw, or greasy foods that may burden the Spleen and Stomach. Avoid consuming highly acidic foods (such as vinegar or citrus) at the same time as taking Long Gu, as acids may react with its calcium carbonate content.

Botanical Description

Physical characteristics and morphology of the Long Gu source mineral

Long Gu (龙骨) is not a botanical product. It is the fossilized bone of large ancient mammals, primarily from the Neogene and Pleistocene periods (roughly 20,000 to several million years ago). The animals whose bones constitute Long Gu include species of three-toed horse (Hipparion), elephant-relatives (Stegodon, mastodons), rhinoceros, deer, cattle, and other large mammals. These fossils are excavated from underground deposits in sedimentary layers, riverbanks, cave sites, and loess plateaus across northern and central China.

Two main commercial forms exist. Bai Long Gu (White Dragon Bone) appears as irregularly shaped bone-like fragments, greyish-white to pale yellow-brown on the surface, hard and dense, with a powdery white cross-section. Wu Hua Long Gu (Five-Coloured Dragon Bone) is lighter and more brittle, with a distinctive marbled appearance showing bands of ivory-white, blue-grey, and reddish-brown. Both forms are strongly hygroscopic and will stick to the tongue when licked, a classic authentication test.

Sourcing & Harvesting

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

Harvesting season

Year-round collection (excavation). Fossil deposits are mined whenever accessible. No seasonal restriction applies, as this is a fossilized mineral substance, not a living organism.

Primary growing regions

Long Gu is excavated rather than cultivated. Historically, the finest specimens were said to come from Shanxi (山西), Inner Mongolia (内蒙古), and Shaanxi (陕西) provinces, which remain the primary source regions. Additional deposits are found in Henan (河南), Hebei (河北), Qinghai (青海), Sichuan (四川), and Yunnan (云南). The classical text Lei Gong Pao Zhi Lun noted specimens from Tanzhou, Cangzhou, and Taiyuan as highest quality. Authentic Wu Hua Long Gu (Five-Coloured Dragon Bone) from the Shanxi-Shaanxi region is considered the most prized dao di material.

Quality indicators

Good quality Bai Long Gu (White Dragon Bone) should be hard, dense, white to greyish-white in colour, with a fine powdery cross-section. When broken, the surface should be smooth and chalk-like. It should have strong hygroscopic (moisture-absorbing) properties and will readily stick to the tongue when licked (a classic authentication test known as 舐之着舌). Good quality Wu Hua Long Gu (Five-Coloured Dragon Bone) should be lighter in weight, easily breakable in layers, showing distinct marbled patterns of ivory-white interspersed with blue-grey and reddish-brown bands, resembling marble. It too should be strongly hygroscopic and tongue-adhering. Both forms should be odourless and tasteless. Avoid specimens that are excessively heavy and stone-like (may indicate dinosaur fossils with high fluoride), lack tongue-adhering property, or show signs of being processed modern animal bone (typically lacking the characteristic porous microstructure and marbled colouration).

Classical Texts

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

Shen Nong Ben Cao Jing (《神农本草经》)

Chinese: 主咳逆，泄痢脓血，女子漏下，癥瘕坚结，小儿热气惊痫。

English: It mainly treats cough with counterflow of Qi, diarrhea and dysentery with pus and blood, vaginal discharge in women, abdominal masses and hard bindings, and fright epilepsy with Heat in children.

Ming Yi Bie Lu (《名医别录》)

Chinese: 疗心腹烦满，四肢痿枯，汗出，夜卧自惊，恚怒，伏气在心下不得喘息……养精神，定魂魄，安五脏。

English: It treats vexation and fullness of the Heart and abdomen, withering of the four limbs, sweating, startling during sleep at night, anger and irritability, and hidden Qi below the Heart causing difficulty breathing. It nourishes the spirit, settles the ethereal and corporeal souls, and calms the five Zang organs.

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

Chinese: 龙骨，质最粘涩，具有翕收之力，故能收敛元气，镇安精神，固涩滑脱。

English: Dragon Bone, being extremely adhesive and astringent in quality, possesses a gathering and collecting power. Therefore it can collect the original Qi, stabilize and calm the spirit, and secure what is slipping away.

Ben Cao Jing Bai Zhong Lu (《本草经百种录》)

Chinese: 龙骨最粘涩，能收敛正气，凡心神耗散，肠胃滑脱之疾，皆能已之。且敛正气而不敛邪气。

English: Dragon Bone is most adhesive and astringent, able to collect the upright Qi. All conditions of dissipated Heart-spirit and slipping of the intestines and stomach can be treated by it. Moreover, it collects the upright Qi without collecting pathogenic Qi.

Historical Context

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

Long Gu was first recorded in the Shen Nong Ben Cao Jing (circa 100 AD) as a superior-grade medicine, where it was described as treating spirit disorders, fright epilepsy, and various forms of fluid leakage. For nearly two millennia, it was genuinely believed to be the bones of dragons. Li Shizhen in the Ben Cao Gang Mu (16th century) was among the first to critically examine this belief, and he listed multiple subcategories of "dragon" material including teeth, horn, brain, and saliva. It was not until after 1950 that scientific investigation confirmed Long Gu to be fossilized mammalian bones from the Pleistocene and Neogene eras.

Perhaps the most famous story involving Long Gu comes from 1899: the Qing dynasty scholar Wang Yirong, who was ill with malaria, purchased Long Gu from a pharmacy and noticed inscriptions carved on certain pieces. This led to the identification of oracle bone script (甲骨文), the earliest known form of Chinese writing, which had been ground up as medicine for centuries. This discovery profoundly impacted Chinese archaeology and historiography.

Zhang Xichun (张锡纯), the renowned late-Qing and early-Republican physician, greatly valued Long Gu. He emphasized using it raw (sheng) for most clinical applications and reserved the calcined form (duan) only for emergencies such as severe uterine bleeding. He observed that Long Gu "collects the upright Qi without collecting pathogenic Qi," making it safe even in conditions where exterior pathogens had not been fully resolved, as demonstrated in Zhang Zhongjing's formulas like Chai Hu Jia Long Gu Mu Li Tang. Since the Chinese Pharmacopoeia dropped Long Gu after its 1985 edition and the 2010 Fossil Protection Regulations further restricted its mining, the herb has become increasingly scarce, stimulating research into substitutes such as calcined pig bone.

Modern Research

3 published studies investigating the pharmacological effects or clinical outcomes of Long Gu

1

Taxonomic Examination of Longgu (Fossilia Ossis Mastodi) and Longchi (Dens Draconis) from Japanese and Chinese Crude Drug Markets (Taxonomic Study, 2017)

Oguri K, Nishioka Y, Kobayashi Y, Takahashi K. Journal of Natural Medicines, 2017, 71(3): 463-471.

This study examined over 20,000 fossil fragments from Long Gu and Long Chi market samples. The researchers classified 246 identifiable fossils into nine mammalian families, confirming that Long Gu originates primarily from large Pleistocene mammals. The study highlighted the urgent need for substitute development due to resource depletion.

2

Long Gu (Os Draconis): Textual Research, Modern Scientific Evaluation, and Quality Control Challenges (Narrative Review, 2025)

Cai et al. Journal of Ethnopharmacology, 2025 (published online February 2025).

This comprehensive review traced the evolution of Long Gu from mythological origins to scientific identification as fossilized mammalian bioapatite. Authentic Wu Hua Long Gu from the Shanxi-Shaanxi region was found to be primarily carbonated hydroxyapatite with high porosity (over 35%) and a distinctive trace element profile featuring zinc and strontium. The review highlighted a critical market crisis, with widespread adulteration by fluoride-rich dinosaur fossils and processed modern bones.

Link
3

Modern Research and Application of Longgu (Review Article, 2017)

Zhongguo Zhong Yao Za Zhi (China Journal of Chinese Materia Medica), 2017.

This Chinese-language review summarized the chemical composition, pharmacological activities, and clinical applications of Long Gu. It confirmed sedative, hypnotic, and anticonvulsant effects, as well as blood coagulation-promoting activity due to its high calcium content. The review also discussed the challenges posed by fossil resource depletion and the search for viable substitutes.

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.