Herb Resin / Sap (树脂 shù zhī / 汁 zhī)

Chen Xiang

Agarwood · 沉香

Aquilaria sinensis (Lour.) Gilg · Lignum Aquilariae Resinatum

Also known as: Aloeswood, Eaglewood, Chenxiang,

Chen Xiang (Agarwood) plant

Images shown are for educational purposes only

Chen Xiang (Agarwood) is a rare and aromatic resinous wood prized in Chinese medicine for its ability to relieve abdominal pain and bloating, settle nausea and hiccups, and calm wheezing caused by weak Kidney function. It works by warming the digestive system and directing the body's Qi powerfully downward, making it especially helpful for conditions where things feel stuck or are rising when they should be descending.

Category Qi-regulating herbs (理气药)
Therapeutic focus Digestive Health Respiratory Health Abdominal Pain Relief Kidney Health

TCM Properties

Temperature

Slightly Warm

Taste

Acrid / Pungent (辛 xīn), Bitter (苦 kǔ)

Channels entered

Spleen, Stomach, Kidneys

Parts used

Resin / Sap (树脂 shù zhī / 汁 zhī)

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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 Chen Xiang does in the body, explained in both everyday and TCM terms

Therapeutic focus

In practical terms, Chen Xiang is primarily used to support these areas of health:

Digestive Health Respiratory Health Abdominal Pain Relief Kidney Health

TCM Actions

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

Moves Qi and Alleviates Pain Warms the Middle Burner and Stops Vomiting Directs Rebellious Qi Downward and Stops Hiccup Aids the Kidneys in Grasping Qi

How these actions work

'Promotes the movement of Qi and alleviates pain' means Chen Xiang helps break up stagnation when Qi gets stuck in the chest or abdomen, causing feelings of fullness, bloating, or pain. Its pungent taste disperses blockages while its warm nature drives out internal cold. This action is especially relevant when cold weather, emotional stress, or dietary factors cause the body's Qi to stall in the middle and lower torso.

'Warms the middle and stops vomiting' refers to Chen Xiang's ability to warm a cold Stomach and restore its natural downward movement. The Stomach's job is to push food downward; when cold disrupts this, food and fluids rebel upward, causing nausea, vomiting, or hiccups. Chen Xiang's bitter taste and heavy, sinking nature redirect this rebellious upward flow back downward, settling the Stomach.

'Warms the Kidneys and helps grasp Qi to calm wheezing' describes one of Chen Xiang's most distinctive functions. In TCM, the Kidneys are supposed to "grasp" or anchor the Qi that the Lungs breathe in. When the Kidneys are weak and cold, they lose this anchoring ability, and Qi floats upward unchecked, causing breathlessness and wheezing where the person can exhale but struggles to inhale deeply. Chen Xiang warms Kidney Yang and, because its nature is heavy and descending, it draws rebellious Qi back down to its root. Classical texts describe it as the foremost herb for directing Qi downward (降气之最).

Patterns Addressed

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

Why Chen Xiang addresses this pattern

Chen Xiang's pungent, aromatic nature disperses cold that has congealed in the chest and abdomen, while its warm temperature directly counteracts the pathogenic cold causing this pattern. Its bitter taste descends and moves stagnant Qi. Together, these properties break up the combination of cold and Qi blockage that causes distending pain in the chest and belly. The herb enters the Spleen and Stomach channels, placing it precisely where this cold-stagnation pattern tends to lodge.

A practitioner would look for one or more of these signs

Abdominal Pain

Cold, distending pain in the abdomen that improves with warmth

Chest Pain

Sense of fullness and stuffiness in the chest

Post-Surgical Constipation And Bloating

Abdominal bloating worsened by cold food or weather

Commonly Used For

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

Arises from: Kidney not Grasping Qi

TCM Interpretation

TCM views chronic asthma not simply as a lung problem, but often as a failure of communication between the Lungs above and the Kidneys below. The Lungs govern breathing, but the Kidneys must anchor and "grasp" the inhaled Qi. When Kidney Yang grows weak from chronic illness, aging, or overwork, it cannot hold Qi down. Qi rebels upward and accumulates in the chest, causing wheezing where exhalation is easy but the breath cannot be drawn deeply inward. This is what TCM calls an "upper excess, lower deficiency" (上盛下虚) condition.

Why Chen Xiang Helps

Chen Xiang addresses the root of this type of asthma by warming Kidney Yang and physically drawing Qi downward. Its dense, heavy resinous nature gives it a powerful descending action that redirects rebellious Qi from the chest back to the Kidneys, restoring the Kidney's ability to grasp Qi. Unlike herbs that only open the Lungs, Chen Xiang works from the bottom up, strengthening the anchor point. This is why it appears in classical formulas for deficiency-type wheezing alongside Kidney-warming herbs like Rou Gui (cinnamon bark) and Fu Zi (aconite).

Also commonly used for

Post-Surgical Constipation And Bloating

Abdominal distension from cold and Qi stagnation

Nausea

From cold Stomach with upward rebellious Qi

Epigastric Fullness And Pain Relieved By Vomiting

Cold-type vomiting of clear fluids

Hiccups

Persistent hiccups from Stomach cold

Wheezing

Chronic wheezing from Kidney failing to grasp Qi

Exertional Dyspnea

Shortness of breath from lower-body deficiency

Chest Pain

Chest fullness and pain from cold Qi stagnation

Constipation

Constipation from Qi deficiency in the Large Intestine (虚秘)

Herb Properties

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

Temperature

Slightly Warm

Taste

Acrid / Pungent (辛 xīn), Bitter (苦 kǔ)

Channels Entered

Spleen Stomach Kidneys

Parts Used

Resin / Sap (树脂 shù zhī / 汁 zhī)

Dosage & Preparation

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

Standard dosage

1-5g

Maximum dosage

Generally should not exceed 5g per dose in decoction. When taken as ground powder or water-ground juice, the typical maximum is 1.5-2g per dose.

Dosage notes

Chen Xiang is a precious and potent aromatic herb used in small doses. For Qi stagnation with chest and abdominal pain, 1-3g is typical. For warming the Middle Burner to stop vomiting, 1-3g is standard. For grasping Kidney Qi to calm wheezing (纳气平喘), 1-5g may be used. When combined with Kidney-tonifying formulas such as a modified Liu Wei Di Huang Wan (as described in the Ben Cao Hui Yan), a small amount of Chen Xiang juice (数分, several fen) is ground separately and stirred into the strained decoction. Higher doses are not more effective and may cause excessive downward movement of Qi, leading to flatulence, poor appetite, and deficiency symptoms with prolonged use.

Preparation

Chen Xiang should NOT be decocted in the normal way with other herbs. Because it is highly aromatic and its therapeutic value depends on volatile oils and resinous compounds that are destroyed by prolonged boiling, it requires special preparation. The preferred traditional method is to grind it into the strained, hot decoction just before drinking (磨汁冲服, literally 'grind juice and dissolve'). Alternatively, it can be ground into a fine powder (研末) and swallowed with warm water or mixed into the strained decoction. If it must be added to a decoction, it should be added in the last 3-5 minutes of cooking (后下, 'add near end'). It is also commonly used in pill and powder formulations.

Processing Methods

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

Processing method

The resinous wood is filed or ground into a fine powder (过120目以上筛网). Because Chen Xiang's volatile aromatic compounds are destroyed by prolonged boiling, powder form is the preferred processing method for internal use.

How it changes properties

Grinding into powder does not change the thermal nature or taste, but it preserves the aromatic volatile oils that would be lost in decoction. The powder form delivers a stronger Qi-moving and descending effect than decocted pieces.

When to use this form

Most internal uses. Chen Xiang powder (0.5-1g per dose) is typically dissolved in warm water or mixed into a strained decoction just before drinking, rather than being boiled with other herbs. This is the standard clinical method.

Common Herb Pairs

These ingredients are traditionally combined with Chen Xiang for enhanced therapeutic effect

Wu Yao
Wu Yao 1:3 (Chen Xiang 1.5g : Wu Yao 4.5-9g)

Chen Xiang descends Qi powerfully downward while Wu Yao warms and disperses stagnant Qi in all directions. Together they form a potent Qi-moving pair that breaks up cold-stagnation in the chest and abdomen from multiple angles. Wu Yao is lighter and more dispersing; Chen Xiang is heavier and more sinking, so the pair covers both upward-spreading and downward-directing movement.

When to use: Cold-type Qi stagnation causing chest and abdominal distension, fullness, and pain. This is the core pairing in Si Mo Tang (Four Milled Herb Decoction) for severe Qi blockage.

Rou Gui
Rou Gui 1:1 (Chen Xiang 1-1.5g : Rou Gui 1-1.5g)

Chen Xiang warms the Kidneys and directs Qi downward, while Rou Gui (cinnamon bark) strongly warms Kidney Yang and the Ming Men fire. The pair reinforces Kidney warmth from two directions: Rou Gui through strong Yang supplementation and Chen Xiang through Qi-directing and anchoring. Together they warm the lower body and restore the Kidneys' ability to grasp Qi.

When to use: Kidney Yang Deficiency causing wheezing with difficulty inhaling, cold lower back and knees, or cold-type hernial pain. Used together in formulas like Hei Xi Dan.

Mu Xiang
Mu Xiang 1:1 to 1:2 (Chen Xiang 1-3g : Mu Xiang 3-6g)

Both herbs regulate Qi, but Mu Xiang (costus root) focuses on moving Qi through the Spleen and Stomach to relieve food stagnation and intestinal cramping, while Chen Xiang descends rebellious Qi and warms cold in the lower body. Combined, they address Qi stagnation across the entire digestive tract with complementary mechanisms: Mu Xiang dispersing laterally and Chen Xiang sinking downward.

When to use: Abdominal bloating and pain with both upper Qi stagnation and lower cold, such as in chronic digestive disorders with a combination of food stagnation and cold accumulation.

Lai Fu Zi
Lai Fu Zi 1:2 to 1:3 (Chen Xiang 1-3g : Fu Zi 3-9g)

Fu Zi (aconite) is the strongest Yang-restoring herb, rescuing collapsed Yang and warming the entire body. Chen Xiang adds Qi-directing and Kidney-warming functions. Together they powerfully warm the Kidneys and direct fire back to its source (引火归元), addressing severe Kidney Yang Deficiency with rebellious Qi rising upward.

When to use: Severe Kidney Yang Deficiency with wheezing, cold extremities, and Qi rebelling upward. This combination appears in Hei Xi Dan for critical lower-body cold with upper-body rebellious symptoms.

Key Formulas

These well-known formulas feature Chen Xiang in a prominent role

Si Mo Tang 四磨湯 King

Si Mo Tang (Four Milled Herb Decoction) is the formula most closely associated with Chen Xiang's core Qi-moving action. All four herbs (Chen Xiang, Wu Yao, Bing Lang, Ren Shen) are ground individually and taken as a draft. Chen Xiang serves as King, showcasing its signature ability to powerfully descend Qi and disperse cold stagnation in the chest and abdomen. This formula is widely used in modern practice for postoperative abdominal distension and Qi stagnation.

Nuan Gan Jian 暖肝煎 Deputy

Nuan Gan Jian (Warm the Liver Brew) from Jing Yue Quan Shu uses Chen Xiang as Deputy to warm the Liver and Kidney channels and promote Qi movement. In this formula for cold-type hernial pain and lower abdominal cold, Chen Xiang demonstrates its ability to direct warm Qi downward to the lower body, complementing the warming action of Xiao Hui Xiang and Rou Gui.

Hei Xi Dan 黑錫丹 Assistant

Hei Xi Dan (Black Tin Elixir) from the Tai Ping Hui Min He Ji Ju Fang treats severe Kidney Yang Deficiency with rebellious Qi causing wheezing. Chen Xiang plays Assistant here, using its sinking, descending nature to draw rebellious Qi back down to the Kidneys. This formula best demonstrates Chen Xiang's unique "warming the Kidneys to grasp Qi" (纳气平喘) function.

Comparable Ingredients

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

Mu Xiang
Chen Xiang vs Mu Xiang

Both regulate Qi and relieve abdominal pain, but they differ in direction and range. Mu Xiang (costus root) is the primary Qi-mover for the Spleen, Stomach, and Large Intestine, excelling at relieving food stagnation, diarrhea with tenesmus, and general digestive cramping. Chen Xiang has a stronger descending and sinking quality and uniquely enters the Kidney channel, giving it the ability to warm the Kidneys and help grasp Qi for wheezing. Choose Mu Xiang for straightforward digestive Qi stagnation; choose Chen Xiang when the problem also involves lower-body cold, rebellious Qi rising upward, or Kidney involvement.

Tan Xiang
Chen Xiang vs Tan Xiang

Both are aromatic woods that move Qi and relieve pain, but they target different areas. Tan Xiang (sandalwood) is pungent, warm, and enters the Spleen, Stomach, and Lung channels, excelling at relieving chest pain and angina-like symptoms in the upper body. Chen Xiang's action is more descending and reaches the Kidneys, making it better for lower abdominal pain, Kidney-type wheezing, and conditions where Qi needs to be directed downward. Choose Tan Xiang for chest-focused Qi pain; choose Chen Xiang when the condition involves the lower body or requires powerful downward-directing action.

Jiang Xiang
Chen Xiang vs Jiang Xiang

Jiang Xiang (dalbergia heartwood) is also a fragrant wood that moves Qi and alleviates pain, but it additionally invigorates Blood and stops bleeding. Jiang Xiang is better suited for traumatic injuries, chest pain with Blood stasis, and bleeding due to stasis. Chen Xiang does not move Blood significantly; its strength lies in warming the Kidneys, directing Qi downward, and addressing cold-type Qi stagnation and deficiency-type wheezing. Choose Jiang Xiang when Blood stasis is part of the picture; choose Chen Xiang for cold-predominant Qi disorders with Kidney involvement.

Common Substitutes & Adulterants

Related species and common adulterations to be aware of when sourcing Chen Xiang

Chen Xiang is one of the most frequently adulterated herbs in the Chinese medicine market due to its extremely high value. Common adulterants include: (1) Non-resinous wood from Aquilaria trees (white wood without agarwood formation), which has been soaked in artificial fragrance oils or dyed with dark colouring to mimic authentic agarwood. (2) Wood from entirely different plant families (Lauraceae, Burseraceae) treated with synthetic fragrance to imitate the scent. (3) Lower-grade agarwood injected with additional resins or oils to increase weight and apparent quality. To identify authentic Chen Xiang: burn a small piece and observe white smoke with visible oil seepage and a clean, sweet agarwood fragrance. Counterfeit material produces black smoke and smells of burning wood or synthetic perfume. Laboratory testing of ethanol extractives (must be at least 15%) and TLC comparison with reference material provide definitive identification.

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

Toxicity Classification

Classical Chinese pharmacopoeia toxicity rating for Chen Xiang

Non-toxic

Chen Xiang is classified as non-toxic in both classical sources and the Chinese Pharmacopoeia. The Hai Yao Ben Cao (Tang dynasty) explicitly states it is "without toxicity" (无毒). No toxic components have been identified in the resinous heartwood at standard medicinal doses. Safety studies on Aquilaria extracts in animal models have shown no significant toxic reactions at doses of 2000 mg/kg over 14 days. However, excessive oral consumption may cause gastrointestinal discomfort including abdominal pain and loose stools in sensitive individuals, and prolonged use without appropriate indication may lead to Qi depletion symptoms as warned in classical texts.

Contraindications

Situations where Chen Xiang should not be used or requires extra caution

Caution

Yin deficiency with Fire flaring (阴虚火旺). Chen Xiang is warm and aromatic, which can further deplete Yin fluids and aggravate internal Heat in those with Yin deficiency patterns. Classical sources such as the Ben Cao Jing Shu specifically warn against its use in this context.

Caution

Qi deficiency with sinking (气虚下陷). Chen Xiang's primary direction is downward-moving, which can worsen conditions where Qi is already collapsing or sinking, such as in severe fatigue with organ prolapse.

Caution

Heat patterns in the Heart channel with excess Fire (心经有实邪). As noted in the Ben Cao Jing Shu, when there is real excess Heat in the Heart, the warming nature of Chen Xiang is inappropriate and may worsen the condition.

Caution

Overuse or prolonged use without appropriate indication. The Ben Jing Feng Yuan warns that Chen Xiang 'descends more than it ascends' and long-term use may lead to excessive downward movement of Qi, manifesting as uncontrollable flatulence, poor appetite, sallow complexion, and various deficiency symptoms.

Special Populations

Important considerations for pregnancy, breastfeeding, and pediatric use

Pregnancy

Use with caution during pregnancy. Chen Xiang is a Qi-moving aromatic herb, and its downward-directing and Qi-mobilizing actions could theoretically stimulate uterine activity or disturb fetal Qi. Classical and modern Chinese sources consistently list pregnant women (孕妇) as a population that should either avoid or use Chen Xiang with caution. It is not classified as absolutely contraindicated in pregnancy, but should only be used when specifically indicated and under practitioner supervision.

Breastfeeding

No specific classical or modern contraindication exists for Chen Xiang during breastfeeding. However, as an aromatic Qi-moving herb with warming properties, it should be used cautiously and only when clearly indicated. There is insufficient data on whether its volatile components transfer through breast milk. Practitioners generally advise conservative use in nursing mothers, at reduced doses and for limited duration.

Children

Chen Xiang may be used in children when specifically indicated for conditions such as Qi stagnation with vomiting or wheezing, but dosage should be reduced proportionally according to age and body weight (typically one-third to one-half the adult dose). Due to the herb's aromatic, warm, and Qi-moving nature, it should be used for short courses only. It is not commonly used as a standalone pediatric herb but appears in paediatric formulas. Avoid use in young children with Yin deficiency or Heat patterns.

Drug Interactions

If you are taking pharmaceutical medications, be aware of these potential interactions with Chen Xiang

No well-documented pharmaceutical drug interactions have been established for Chen Xiang through rigorous clinical studies. However, based on its known pharmacological properties, the following theoretical considerations apply:

  • Sedative and CNS-depressant medications: Agarwood extracts have demonstrated sedative and anxiolytic effects in animal models, possibly through GABAergic modulation. Concurrent use with benzodiazepines, barbiturates, or other CNS depressants could theoretically have additive effects.
  • Gastrointestinal motility drugs: Chen Xiang has been shown to inhibit intestinal smooth muscle contraction and reduce acetylcholine-induced gut spasm. This could theoretically interact with prokinetic agents (metoclopramide, domperidone) by opposing their effects, or enhance the effects of antispasmodic medications.
  • Anticoagulant and antiplatelet drugs: While no direct interaction data exists, some chromone and sesquiterpene compounds from agarwood have shown anti-inflammatory activity. Caution may be warranted with concurrent anticoagulant therapy until more data is available.

Clinical interaction data remains limited. Patients on medications should inform their healthcare provider before using Chen Xiang.

Dietary Advice

Foods and dietary considerations when taking Chen Xiang

While taking Chen Xiang, avoid cold and raw foods (ice water, raw salads, cold fruits) as these can counteract its warming, Qi-moving effects and impair Spleen function. Since Chen Xiang warms the Middle Burner and descends Qi, it works best when supported by a diet of warm, easily digestible foods such as congee, soups, and cooked vegetables. Avoid excessively spicy or greasy foods, which can generate additional Heat or Dampness and complicate the clinical picture. Those taking Chen Xiang for Kidney Qi grasping should also limit caffeine and stimulants, which can agitate Qi upward.

Botanical Description

Physical characteristics and morphology of the Chen Xiang source plant

Aquilaria sinensis (Lour.) Gilg is an evergreen tree in the family Thymelaeaceae (formerly sometimes placed in Thymeleaceae), native to southern China. It typically reaches 5 to 15 metres in height, though specimens in optimal conditions can grow up to 40 metres with trunk diameters up to 1.8 metres. The bark is smooth and whitish to greyish in colour. The leaves are alternate, leathery, obovate to elliptic, measuring 5 to 11 cm long and 2 to 4 cm wide, with an entire margin, a short acuminate apex, and a broadly cuneate base. Small yellowish-green, fragrant flowers appear in terminal or axillary umbels, typically blooming around April. The fruits are woody, obovoid capsules about 2.5 to 3 cm long containing winged seeds, maturing around July.

The tree thrives in lowland tropical and subtropical forests, on hillsides, ridges, and along roadsides in sunny positions, at elevations up to 750 metres. It prefers warm, humid climates with annual rainfall of 1,500 to 6,500 mm and does well on both heavy soils derived from metamorphic rocks and sandy loams from sandstone. The medicinally valuable part, agarwood (Chen Xiang), is not the normal wood of the tree. It forms as a pathological product: when the tree is wounded by insects, storms, or fungal infection (particularly Phaeoacremonium species), it produces a dark, fragrant resin as a defence mechanism. This resin saturates the heartwood over time, dramatically increasing its density and altering its colour. Resin-impregnated wood is usually found only in trees older than 20 years. The species is classified as Vulnerable on the IUCN Red List and is listed under CITES Appendix II.

Sourcing & Harvesting

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

Harvesting season

Year-round (全年均可采收). The resin-containing heartwood can be harvested at any time, though traditionally autumn and winter are preferred because the wood is drier with less moisture and purer fragrance. Trees must be at least 10 to 30 years old before meaningful resin formation occurs, with the highest quality agarwood coming from trees over 200 years old.

Primary growing regions

The premium dao di (道地药材) source of Chen Xiang is Hainan Island, China, which has been celebrated since the Song dynasty as producing the finest quality agarwood. Li Shizhen praised it in the Ben Cao Gang Mu as "one piece worth ten thousand coins, the best under heaven" (海南沉香，一片万钱，冠绝天下). Other important Chinese producing regions include Guangdong province (particularly the Dongguan area, where the local variety is called "Guan Xiang" or "daughter's fragrance"), Guangxi, and Fujian. Internationally, high-quality agarwood also comes from Vietnam (especially the Nha Trang and Hue An regions), Cambodia, Malaysia, and Indonesia, though these are typically derived from related species such as Aquilaria crassna and A. malaccensis rather than the Chinese Pharmacopoeia species A. sinensis.

Quality indicators

The highest quality Chen Xiang (agarwood) is dense, dark, and resin-rich. The gold standard is whether the piece sinks in water (沉水): pieces that sink completely contain the most resin and are the most valuable. Pieces that partially sink (半沉半浮) are of medium grade, while those that float are lower quality (classified historically as "huang shu xiang" or yellow-ripe incense). The surface should show a clear pattern of dark brown-to-black resinous areas interspersed with yellowish-white wood. Good quality pieces have a firm, solid texture and are difficult to break. The fragrance should be distinctly aromatic, complex, and sweet when the piece is gently heated. It should not smell like burnt wood or artificial perfume. When burned, authentic Chen Xiang produces white smoke with visible oil seeping from the surface. The taste is bitter. Per the Chinese Pharmacopoeia, the ethanol-soluble extractives should not be less than 15%. Cross-section examination should show resin-filled ray cells and medullary tissue appearing brown under microscopy.

Classical Texts

Key passages from the classical Chinese medical texts that describe Chen Xiang and its therapeutic uses

Ming Yi Bie Lu (名医别录, c. 500 AD)

Original: 沉香，疗风水毒肿，去恶气。
Translation: "Chen Xiang treats wind-water toxin swelling and eliminates foul Qi." This is among the earliest recorded medicinal uses of agarwood, reflecting its ability to move Qi and dispel pathogenic factors.

Ben Cao Tong Xuan (本草通玄)

Original: 沉香，温而不燥，行而不泄，扶脾而运行不倦，达肾而导火归元，有降气之功，无破气之害，洵为良品。
Translation: "Chen Xiang is warm without being drying, moves [Qi] without draining, supports the Spleen and keeps its transport tireless, reaches the Kidney and guides Fire back to its source. It has the power to descend Qi without the harm of breaking Qi. Truly a superior substance."

Ben Cao Xin Bian (本草新编)

Original: 沉香，温肾而又通心，用黄连、肉桂以交心肾者，不若用沉香更为省事，一药而两用之也。
Translation: "Chen Xiang warms the Kidney and also opens communication with the Heart. Those who use Huang Lian and Rou Gui to harmonize the Heart-Kidney axis would find it simpler to use Chen Xiang, which serves both purposes in a single substance."

Ben Cao Gang Mu (本草纲目, Li Shizhen, 1578)

Original: 治上热下寒，气逆喘急，大肠虚闭。
Translation: "Treats upper Heat with lower Cold, counterflow Qi with urgent wheezing, and deficiency-type constipation of the Large Intestine."

Ben Cao Jing Shu (本草经疏)

Original: 沉香治冷气、逆气，气郁气结，殊为要药。
Translation: "Chen Xiang treats cold Qi, counterflow Qi, Qi depression, and Qi binding. It is truly an essential medicine [for these conditions]."

Historical Context

The history and evolution of Chen Xiang's use in Chinese medicine over the centuries

Chen Xiang (沉香) literally means "sinking fragrance," named because high-quality resinous pieces are dense enough to sink in water. It ranks first among the classical "four famous fragrances" (沉檀龙麝, alongside sandalwood, dragon's ambergris, and musk). Its earliest medicinal record appears in the Ming Yi Bie Lu (Miscellaneous Records of Famous Physicians), attributed to Tao Hongjing around the 5th-6th century, giving it over 1,500 years of documented clinical use.

The cultural significance of Chen Xiang is immense. Hong Kong literally means "fragrant harbor" (香港), a name derived from its historical role as a major agarwood export port from the Tang through Ming dynasties. During the Song dynasty, the statesman Ding Wei was exiled to Hainan and wrote the Tian Xiang Zhuan (Record of Heavenly Fragrance), praising Hainan agarwood as incomparably superior to all other sources. Su Shi (Su Dongpo), also exiled to Hainan, wrote the famous Chen Xiang Shan Zi Fu (Rhapsody on a Chen Xiang Mountain Ornament) as a birthday gift for his brother, celebrating the wood as "surpassing all others, with the hardness of gold and luster of jade." By the Ming and Qing dynasties, Chen Xiang's clinical applications had matured, appearing in over 160 traditional formulas and remaining a key ingredient in more than 160 modern Chinese patent medicines.

In Buddhist, Daoist, and Confucian traditions, Chen Xiang incense has served as a spiritual aid for meditation and offerings. The Yi Lin Zuan Yao praised it as able to "regulate all disordered Qi" (凡一切不调之气皆能调之). It is also one of the famous "Ten Great Guangdong Medicines" (十大广药).

Modern Research

4 published studies investigating the pharmacological effects or clinical outcomes of Chen Xiang

1

Chemical Constituents and Pharmacological Activity of Agarwood and Aquilaria Plants (Review, 2018)

Wang S, Yu Z, Wang C, Wu C, Guo P, Wei J. Molecules, 2018, 23(2): 342.

This comprehensive review summarized over 300 compounds isolated from agarwood and Aquilaria plants, primarily sesquiterpenes and 2-(2-phenylethyl)chromone derivatives. Pharmacological activities documented included gastrointestinal smooth muscle relaxation, sedative and anxiolytic effects, anti-inflammatory activity, antibacterial properties, and cytotoxicity against certain cancer cell lines. The review confirmed the scientific basis for traditional uses in digestive complaints, respiratory disorders, and calming applications.

2

Aquilaria Species Distribution, Phytochemicals, Pharmacological Uses, and Agarwood Grading System (Review, 2021)

Li W, Chen HQ, Wang H, Mei WL, Dai HF. Molecules, 2021, 26(24): 7708.

This review covered the pharmacological research on 17 Aquilaria species, focusing on antibacterial, anti-tumor, antidepressant, antioxidant, and cardiovascular protective activities. The main bioactive compounds, sesquiterpenes and chromones, were shown to possess diverse pharmacological properties including sedation, analgesia, anti-inflammation, anti-asthmatic, and hypoglycemic effects, supporting the traditional TCM applications of agarwood.

3

The Therapeutic Potential of Agarwood as an Antimicrobial and Anti-Inflammatory Agent: A Scoping Review (2024)

Published in Nutrients-related journal, 2024. Available via PMC.

This scoping review found that Aquilaria sinensis is the most-studied species for antimicrobial and anti-inflammatory properties. The review documented that agarwood extracts demonstrated potent antifungal activity and significant anti-inflammatory effects, with bioactive compounds including sesquiterpenes and chromone derivatives modulating inflammatory pathways.

4

Agarwood as a Neuroprotective Agent: A Comprehensive Review (2025)

Published in Phytochemistry Reviews, Springer Nature, 2025.

This recent review highlighted agarwood's significant neuroprotective potential. Bioactive compounds, particularly sesquiterpenoids, flavonoids, and chromones, were shown to modulate neurotransmitter balance, regulate GABAergic pathways, suppress neuroinflammation, reduce HPA axis overactivity, and promote neurite outgrowth. These findings support the traditional use of agarwood for calming the spirit and treating anxiety and insomnia.

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.