Herb Resin / Sap (树脂 shù zhī / 汁 zhī)

An Xi Xiang

Benzoin resin · 安息香

Styrax tonkinensis (Pierre) Craib ex Hart. · Benzoinum

Also known as: Benzoin

An Xi Xiang (Benzoin resin) plant

Images shown are for educational purposes only

Benzoin resin is an aromatic substance used in Chinese medicine primarily for emergency situations involving sudden loss of consciousness caused by phlegm blocking the mind. It also helps relieve chest and abdominal pain by promoting circulation, and has a long history of use for postpartum fainting and childhood convulsions. First recorded in the Tang Dynasty materia medica, it remains an ingredient in several classic emergency formulas.

Category Aromatic substances that open the orifices (开窍药)
Therapeutic focus Neurological Emergencies Pain Management Circulation Support Respiratory Health

TCM Properties

Temperature

Neutral

Taste

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

Channels entered

Heart, Liver, Spleen

Parts used

Resin / Sap (树脂 shù zhī / 汁 zhī)

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

Therapeutic focus

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

Neurological Emergencies Pain Management Circulation Support Respiratory Health

TCM Actions

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

Opens the Orifices and Revives Consciousness Dispels Turbidity and Filth Invigorates Blood and Moves Qi Alleviates Pain

How these actions work

'Opens the orifices and revives consciousness' means that An Xi Xiang's aromatic nature can penetrate and unblock the sensory orifices of the Heart when they become obstructed by phlegm or turbid substances. This makes it useful in emergency situations involving sudden loss of consciousness, fainting, or coma. In TCM, the Heart houses the mind (Shen), and when phlegm or foul Qi blocks the Heart's orifices, consciousness is lost. An Xi Xiang's fragrant, penetrating quality helps disperse these obstructions and restore awareness.

'Dispels turbidity and filth' refers to this herb's ability to clear away foul, turbid, or pestilential Qi that can invade the body and cloud the mind. Its strong aromatic properties make it particularly effective against noxious environmental influences, including epidemic pathogens and toxic vapors that cause sudden collapse or delirium.

'Moves Qi and invigorates Blood' means An Xi Xiang promotes the smooth flow of both Qi and Blood. When Qi stagnates, pain results; when Blood is stuck, it causes sharp or fixed pain and conditions like postpartum blood dizziness. The herb's acrid and bitter tastes give it the ability to break through these blockages, which is why it appears in treatments for sudden chest or abdominal pain, and for women who become unconscious after childbirth due to Blood stasis.

'Alleviates pain' follows directly from its Qi-moving and Blood-activating properties. It is particularly suited to pain caused by cold congealing and Qi stagnation in the chest and abdomen. It can even be taken alone as a simple powder in boiling water for sudden heart pain.

Patterns Addressed

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

Why An Xi Xiang addresses this pattern

When cold-phlegm accumulates and obstructs the Heart's orifices, consciousness becomes clouded or lost entirely. An Xi Xiang enters the Heart channel, and its acrid and aromatic nature allows it to penetrate and disperse the cold-phlegm obstruction. Unlike strongly cold-natured orifice-openers, An Xi Xiang's neutral-to-slightly-warm thermal nature makes it particularly suited for cold-type closures (as opposed to heat closures), where the face is pale, the limbs are cold, and the tongue coating is white. Its bitter taste helps to dry and transform accumulated phlegm, while its aromatic quality revives the spirit.

A practitioner would look for one or more of these signs

Loss Of Consciousness

Sudden fainting or collapse with cold limbs and pale face

Lockjaw

Clenched jaw, inability to open mouth

Sputum

Copious phlegm in the throat

Commonly Used For

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

Arises from: Phlegm

TCM Interpretation

In TCM, acute stroke is understood as a sudden disruption of the body's internal balance that causes 'closure' of the orifices. Two main types are distinguished: hot closure (face red, body hot, breath foul) and cold closure (face pale, limbs cold, breathing quiet). In the cold closure type, turbid phlegm congeals in the Heart's orifices due to internal cold and Qi stagnation, blocking the spirit and resulting in unconsciousness, clenched jaw, and a white tongue coating. Wind, phlegm, stasis, and Qi reversal are the key pathogenic factors.

Why An Xi Xiang Helps

An Xi Xiang's aromatic, penetrating nature allows it to break through the phlegm obstruction blocking the Heart orifices, helping to restore consciousness. Its neutral-to-warm thermal nature is appropriate for cold-type closures, where a cooling orifice-opener like Niú Huáng (ox gallstone) would be too cold. Additionally, its ability to invigorate Blood and move Qi addresses the underlying stasis that contributes to stroke. In clinical practice, it is not used alone for stroke but as part of formulas like Su He Xiang Wan, where multiple aromatic and Qi-moving substances work together.

Also commonly used for

Loss Of Consciousness

Sudden collapse from stroke, phlegm obstruction, or toxic exposure

Abdominal Pain

Sudden epigastric or abdominal pain

Postpartum Weakness

Postpartum syncope due to blood stasis

Childhood Febrile Convulsions

Pediatric convulsions with phlegm obstruction

Bronchitis

As an expectorant to promote phlegm discharge

Herb Properties

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

Temperature

Neutral

Taste

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

Channels Entered

Heart Liver Spleen

Parts Used

Resin / Sap (树脂 shù zhī / 汁 zhī)

Dosage & Preparation

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

Standard dosage

0.6-1.5g

Maximum dosage

Generally not exceed 1.5g internally. This herb is primarily used in pills and powders rather than decoctions, and the standard range of 0.6-1.5g represents both the therapeutic and upper safe limit for most clinical situations.

Dosage notes

An Xi Xiang is rarely used in standard decoctions because its resinous nature makes it poorly soluble in water. It is most commonly ground into fine powder and incorporated into pills (丸) or powders (散). For emergency resuscitation in cases of cold-phlegm obstructing the orifices, it is used at the higher end of its range (up to 1.5g) in compound pill formulas such as Su He Xiang Wan. For heart and abdominal pain, classical sources describe taking 0.5-1g of the powdered resin in hot water. It can also be steamed with wine to form a paste (酒蒸成膏) for incorporation into pill formulas. For external use in joint pain, the classical method involves fumigation with the heated resin.

Preparation

Do not decoct in the standard manner. An Xi Xiang is a resin that does not dissolve well in water. It is typically ground into fine powder and taken in pill or powder form (多入丸散用). Alternatively, it can be dissolved in a small amount of warm alcohol or steamed with wine to form a paste before being incorporated into pill formulas. Classical texts specifically warn against processing with fire (修制最忌经火), as excessive direct heat can damage its aromatic properties. For fumigation therapy (external use), the resin is heated gently to produce aromatic smoke directed at the affected area.

Processing Methods

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

Processing method

The raw resin is ground to powder and steeped in grain wine (无灰酒), then heated in a double boiler (重汤煮) until the resin dissolves and can be filtered to remove sand, bark, and impurities. The filtered liquid is then slowly simmered into a thick paste (膏).

How it changes properties

Wine processing enhances the herb's Blood-invigorating and channel-penetrating abilities. The wine's warm, dispersing nature strengthens An Xi Xiang's capacity to move Qi and Blood. The resulting paste form also serves as an excellent binding agent for pill formulations, improving the clinical utility of the preparation.

When to use this form

Used when preparing An Xi Xiang for inclusion in pill formulas such as Su He Xiang Wan and Zhi Bao Dan. The paste acts both as a therapeutic ingredient and as the binding matrix for the pill. This is the standard clinical preparation method described in the classical texts.

Common Herb Pairs

These ingredients are traditionally combined with An Xi Xiang for enhanced therapeutic effect

Su He Xiang
Su He Xiang Su He Xiang 1 : An Xi Xiang 2 (as in Su He Xiang Wan)

Together, An Xi Xiang and Su He Xiang create a powerful aromatic orifice-opening pair that disperses turbid phlegm and revives consciousness. Su He Xiang is stronger at penetrating the orifices and expelling filthy Qi, while An Xi Xiang contributes additional Blood-invigorating and pain-relieving action. They serve as co-King herbs in Su He Xiang Wan.

When to use: Cold-type closure with sudden loss of consciousness, clenched jaw, pale face, and cold limbs, or chest pain from cold congealing in the Heart vessels.

She Xiang
She Xiang She Xiang 1 : An Xi Xiang 2 (She Xiang in smaller doses due to its extreme potency)

Musk (She Xiang) is the most potent orifice-opener in the materia medica, while An Xi Xiang provides complementary aromatic opening with additional Qi-moving and Blood-activating effects. Together they produce a synergistic effect that penetrates all blocked orifices more effectively than either alone.

When to use: Severe closures with unconsciousness, whether from stroke, phlegm obstruction, or toxic exposure, where maximum orifice-opening power is needed.

Wu Ling Zhi
Wu Ling Zhi An Xi Xiang 1 : Wu Ling Zhi 5 (as in the classical formula from Ben Cao Hui Yan)

An Xi Xiang opens orifices and moves Qi, while Wu Ling Zhi (flying squirrel feces) powerfully invigorates Blood and dispels stasis. Together they address both Qi stagnation and Blood stasis simultaneously, particularly useful for postpartum emergencies.

When to use: Postpartum blood dizziness with fainting, abdominal distension, and clenched jaw, where stagnant Blood has clouded consciousness.

Bing Pian
Bing Pian 1:1

Both are aromatic orifice-openers, but Bing Pian (borneol) is slightly cold and better at clearing Heat from the Heart, while An Xi Xiang is neutral and better at moving Qi and Blood. Together they open orifices from two complementary angles, suitable for closures that involve both turbid phlegm and mild heat.

When to use: Phlegm-heat or turbid phlegm blocking the Heart orifices, as in Zhi Bao Dan and Su He Xiang Wan where both herbs appear together.

Key Formulas

These well-known formulas feature An Xi Xiang in a prominent role

Su He Xiang Wan 苏合香丸 King

The definitive warm-opening formula for cold-closure unconsciousness. An Xi Xiang serves as co-King alongside Su He Xiang, showcasing its core orifice-opening and filth-dispersing actions. The original preparation method even uses An Xi Xiang as the binding agent (boiled into a paste with wine to form the pill base), highlighting its central role in the formula.

Zhi Bao Dan 至宝丹 Deputy

One of the 'Three Treasures' of cool-opening formulas for heat-closure unconsciousness. An Xi Xiang serves as Deputy here alongside Bing Pian, providing aromatic orifice-opening and turbidity-dispelling action. This formula demonstrates An Xi Xiang's versatility: although it is neutral in nature, it can be combined with cold herbs like water buffalo horn to treat heat-type closures.

Comparable Ingredients

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

Su He Xiang
An Xi Xiang vs Su He Xiang

Both are warm-type aromatic orifice-openers used for cold-closure unconsciousness. Su He Xiang is stronger at opening orifices and dispersing turbid Qi, making it the primary choice for severe cold closures. An Xi Xiang has a milder orifice-opening effect but adds the ability to invigorate Blood and relieve pain, making it more appropriate when chest or abdominal pain accompanies the closure, or when postpartum blood stasis is involved.

She Xiang
An Xi Xiang vs She Xiang

Musk (She Xiang) is far more powerful at opening orifices and can be used for both hot and cold closures when properly combined. An Xi Xiang's opening power is considerably weaker by comparison. However, An Xi Xiang has Qi-moving and Blood-activating properties that She Xiang lacks, and it does not carry the same risk of damaging Qi through excessive dispersal. An Xi Xiang is also far more accessible, as musk is now extremely rare and regulated.

Shi Chang Pu
An Xi Xiang vs Shi Chang Pu

Both can open the orifices and transform turbid phlegm. Shi Chang Pu (acorus rhizome) is more commonly used in chronic conditions involving phlegm misting the Heart, such as epilepsy, poor memory, or mental confusion, because it is mild enough for daily use. An Xi Xiang is reserved for acute emergencies with sudden loss of consciousness, as it is more aromatic and penetrating but less suited for long-term use.

Identity & Adulterants

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

An Xi Xiang has a long history of adulteration and confusion with related substances. A 2023 molecular diagnostic study found that about 29.6% of commercially available benzoin samples were mixed with plant tissues from other genera. Styrax japonicus resin has been found as a substitute in commercial samples, despite not being an officially recognized source. Sumatra benzoin (from Styrax benzoin), while a legitimate commercial product, has a different chemical profile (containing cinnamic acid, which Siam benzoin lacks) and should be distinguished from the official Chinese Pharmacopoeia source. In China, resins from related domestic species such as粉背安息香 (S. hypoglaucus, now synonymised with S. tonkinensis) and 白叶安息香 have been used as substitutes. Historically, Liquidambar storax balsam has sometimes been confused with benzoin, but it comes from a completely different plant family. Low-quality product may contain bark fragments, sand, stones, or other debris mixed into the resin mass.

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

Toxicity Classification

Classical Chinese pharmacopoeia toxicity rating for An Xi Xiang

Non-toxic

An Xi Xiang is classified as non-toxic in both classical sources (the Xin Xiu Ben Cao states 'neutral, non-toxic') and the modern Chinese Pharmacopoeia. The resin's primary chemical constituents are benzoic acid, coniferyl benzoate, vanillin, and related balsamic acid esters, which have a generally favourable safety profile. The FAO/WHO Expert Committee assessed S. tonkinensis resin and concluded it would not be of safety concern when used as a flavouring agent, establishing a No Adverse Effect Level of 500 mg/kg body weight per day. At standard medicinal doses (0.6-1.5g), no significant toxicity has been reported. However, concentrated benzoin tincture vapour can irritate the eyes, nose, and throat if inhaled at high concentrations.

Contraindications

Situations where An Xi Xiang should not be used or requires extra caution

Caution

Yin deficiency with vigorous Fire (阴虚火旺). The Ben Jing Feng Yuan states: 'Those with Qi deficiency and poor appetite, or Yin deficiency with excessive Fire, must not use this herb.' Its warm, aromatic, dispersing nature can further deplete Yin fluids and aggravate Fire symptoms.

Caution

Qi deficiency with poor appetite (气虚少食). The herb's aromatic, moving nature can further scatter already depleted Qi and impair digestion in those with underlying Qi deficiency of the Spleen and Stomach.

Caution

Pregnancy. An Xi Xiang invigorates Blood and moves Qi, which poses a theoretical risk of disturbing the fetus or promoting uterine contractions. It should be avoided during pregnancy unless specifically prescribed by a qualified practitioner.

Special Populations

Important considerations for pregnancy, breastfeeding, and pediatric use

Pregnancy

Use with caution. An Xi Xiang has Blood-invigorating and Qi-moving properties (行气活血), which could theoretically stimulate uterine contractions or disturb fetal stability. Classical indications include treating postpartum Blood stagnation (产后血晕), which confirms its Blood-moving potency. While it is not listed among the strongest pregnancy-prohibited herbs (like She Xiang or San Leng), its aromatic dispersing nature and Blood-moving action warrant avoidance during pregnancy unless the clinical situation absolutely requires it under expert supervision.

Breastfeeding

No specific classical or modern data addresses the transfer of An Xi Xiang constituents through breast milk. Given its aromatic, dispersing nature and the general principle of caution with Blood-moving substances during the postpartum breastfeeding period, it is advisable to use only when clearly indicated and under practitioner guidance. The resin contains benzoic acid and vanillin, which are generally low in toxicity, but their effects on nursing infants have not been specifically studied.

Children

An Xi Xiang has classical indications for paediatric conditions, particularly childhood Wind convulsions (小儿惊风), where it is typically used in pill or powder form at reduced doses. As with all aromatic orifice-opening herbs, it should only be used in children under the guidance of an experienced practitioner, with dosage scaled appropriately to the child's age and weight. External use of benzoin-containing preparations should be avoided on children under 2 years of age due to the potential for skin sensitisation.

Drug Interactions

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

No well-documented interactions between An Xi Xiang and specific pharmaceutical drugs have been established in peer-reviewed literature. However, given the herb's Blood-invigorating (活血) properties, theoretical caution is warranted when combining it with anticoagulant or antiplatelet medications (such as warfarin, aspirin, or clopidogrel), as there may be an additive effect increasing bleeding risk. Benzoic acid, a major constituent of the resin, is generally well-tolerated and commonly found in food preservatives, but individuals taking medications metabolised through similar pathways should be aware of potential interactions. Patients on any regular medication should consult their healthcare provider before using An Xi Xiang.

Dietary Advice

Foods and dietary considerations when taking An Xi Xiang

While taking An Xi Xiang, avoid cold, raw, and greasy foods that may generate phlegm or obstruct Qi movement, as these would counteract the herb's orifice-opening and Qi-moving effects. Since this herb is often used for emergency revival from phlegm obstruction or stagnation, a light, easily digestible diet supports its therapeutic action. Avoid excessive alcohol unless the resin is being specifically prepared with wine as part of the formula.

Botanical Description

Physical characteristics and morphology of the An Xi Xiang source plant

Styrax tonkinensis (Pierre) Craib ex Hart. (Bái Huā Shù, white flower tree) is a semi-deciduous tree in the Styracaceae family that can grow 6 to 30 metres tall with a dense crown, especially in young specimens. The bark is greyish-brown, and the leaves are alternate, simple, and rounded to ovate. The tree produces racemes of pendulous white, bell-shaped flowers. The fruit is a small, subglobose drupe. The species is fast-growing and can achieve annual height increments of 3 metres during its first three years.

The medicinal product is not the plant itself but the resinous exudate (树脂) collected from the trunk. When the bark is naturally wounded or deliberately incised, the tree secretes a yellowish-white balsamic resin that gradually hardens on exposure to air. This resin, known commercially as Siam benzoin, has a characteristic sweet, vanilla-like, balsamic fragrance. The tree grows in warm, humid environments on mountain slopes and forest edges, in deep, fertile soils at elevations from 30 to 2,400 metres.

Sourcing & Harvesting

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

Harvesting season

Summer and autumn. Trees are typically tapped from 5-10 years of age onward. Classically, resin was collected in the 6th-7th lunar months (roughly July-August). Modern practice favours initial tapping from April to June, with the first exudate being the highest quality milky-white resin.

Primary growing regions

The source plant Styrax tonkinensis is native to Southeast Asia, distributed across southern China, Vietnam, Laos, Cambodia, and Thailand. Historically, benzoin was imported from Persia, Southeast Asian kingdoms (referred to as "Western regions" in Tang Dynasty texts), and Annam (Vietnam). In China, Styrax species capable of producing benzoin grow in Yunnan, Guangxi, Guangdong, Fujian, and Guizhou provinces. The Laotian highlands (Huaphan, Luang Prabang, and Phongsaly provinces) are considered a premier source, producing the highest-quality Siam benzoin. Indonesian Sumatra is the main source of Sumatra benzoin (from S. benzoin). China historically relied heavily on imports, though domestic production from related species has expanded.

Quality indicators

Good quality An Xi Xiang appears as irregular small, slightly flattened pieces or lumps. Naturally exuded resin has an orange-yellow surface with a waxy lustre, and is considered superior. Artificially tapped resin is greyish-white to pale yellowish-white on the surface, in irregular cylindrical or flattened block shapes. The texture should be brittle and easily broken, with a flat, white cross-section that gradually turns yellowish-brown to reddish-brown upon standing. When heated it softens and melts. The aroma should be distinctly fragrant (sweet, balsamic, vanilla-like). When chewed, good quality resin produces a slightly acrid taste with a gritty, sandy sensation. Classical sources advise that resin with strong oiliness, prominent waxy lustre, rich fragrance, and no sand, stone, or bark impurities is best. The first exudate collected from a tree is always the highest quality.

Classical Texts

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

Xīn Xiū Běn Cǎo (《新修本草》, Tang Dynasty)

Original: 安息香，味辛、苦，平，无毒。主心腹恶气鬼疰。出西戎，似松脂，黄黑色为块，新者亦柔韧。

Translation: An Xi Xiang is acrid and bitter in flavour, neutral in nature, and non-toxic. It governs malignant Qi of the Heart and abdomen and ghost-inflicted disorders. It comes from the Western regions, resembles pine resin, is yellowish-black in lumps, and when fresh is also soft and pliable.

Běn Cǎo Gāng Mù (《本草纲目》, Li Shizhen, Ming Dynasty)

Original: 此香辟恶，安息诸邪，故得名。有人说，安息是国名。《梵书》称为拙贝罗香。

Translation: This aromatic substance wards off evil and pacifies (ān xī) all pathogenic influences, hence its name. Some say "An Xi" refers to a country name [the Parthian Empire]. Buddhist texts call it Zhuō Bèi Luó Xiāng.

Běn Jīng Féng Yuán (《本经逢原》)

Original: 凡气虚少食，阴虚多火者禁用。

Translation: It is prohibited in all cases of Qi deficiency with poor appetite, and Yin deficiency with excessive Fire.

Yǒu Yáng Zá Zǔ (《酉阳杂俎》, Duan Chengshi, Tang Dynasty)

Original: 安息香树出自波斯国，称为辟邪树。长二三丈，皮色黄黑。叶有四角，经寒不凋。二月开黄色花，花心微碧。不结实。刻其树皮，胶如饴，名安息香，六七月坚凝时即可取。烧，通神明，辟众恶。

Translation: The benzoin tree comes from Persia and is called the "evil-repelling tree." It grows two to three zhàng tall, with yellowish-black bark. Its leaves have four corners and do not wilt in cold. In the second month it blooms yellow flowers with a slightly blue-green centre. It bears no fruit. When the bark is incised, the sap flows like malt sugar and is called An Xi Xiang. In the sixth and seventh months, when it solidifies, it can be collected. When burned, it reaches the spirits and dispels all evils.

Historical Context

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

An Xi Xiang has one of the most colourful histories of any substance in the Chinese materia medica, intertwined with the ancient Silk Road trade. Its first recorded medicinal use appeared in the Tang Dynasty's Xīn Xiū Běn Cǎo (《新修本草》, 659 CE), making it one of the notable imported aromatics of that era. The name "An Xi" (安息) likely derives from the Parthian Empire (known in Chinese as the An Xi Kingdom, 安息国), the ancient realm roughly corresponding to modern Iran's Khorasan region, through which this resin was traded westward into China. Li Shizhen in the Běn Cǎo Gāng Mù offered an alternative etymology: the herb "pacifies (安) and calms (息) all evils," giving it its name. Buddhist scriptures referred to it as Zhuō Bèi Luó Xiāng (拙贝罗香).

The resin was highly valued in ancient incense culture. The Song Dynasty author Ye Tinggui noted in the Xiāng Pǔ (《香谱》) that while An Xi Xiang was not suited for burning on its own, it excelled at "bringing forth the fragrance of all other incenses" when blended, making it a prized fixative. It became a key ingredient in famous aromatic medicinal formulas such as Sū Hé Xiāng Wán (苏合香丸) from the Tàipíng Huìmín Héjì Jú Fāng, used for resuscitation from stroke and cold-phlegm obstruction. Over the centuries, the botanical source shifted. Ancient records described a tree from Persia, but the modern Chinese Pharmacopoeia (from 1985 onward) specifies Styrax tonkinensis as the official source plant.

Modern Research

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

1

Triterpenoids from the Resin of Styrax tonkinensis and Their Antiproliferative and Differentiation Effects in Human Leukemia HL-60 Cells (Preclinical, 2006)

Wang F, Hua HM, Pei YH, Chen D, Jing YK. Journal of Natural Products, 2006, 69(5): 807-810.

This study isolated triterpenoid compounds from benzoin resin (Styrax tonkinensis) and tested them against human leukemia cells (HL-60). Several triterpenoids showed antiproliferative effects and induced cell differentiation, suggesting potential anticancer properties of benzoin constituents in laboratory settings.

DOI
2

Benzoin Resin: An Overview on Its Production Process, Phytochemistry, Traditional Use and Quality Control (Review, 2023)

He Q, Feng J, Wu M, Xie A, Liu Y. Molecules, 2023, 28(10): 4219.

A comprehensive review covering the production, phytochemistry, traditional uses, and quality control of benzoin resin. The authors identified 63 chemical constituents from benzoin, including balsamic acid esters, lignans, and terpenoids. The review summarized evidence for anti-inflammatory, antipyretic, blood-brain barrier permeability-promoting, and antitumour activities.

PubMed
3

Styrax spp.: Habitat, Phenology, Phytochemicals, Biological Activity and Applications (Review, 2025)

Paparella A, Serio A, Shaltiel-Harpaz L, Revuru B, Kongala PR, Ibdah M. Plants (Basel), 2025, 14(5): 746.

A broad review of the Styrax genus covering phytochemistry and biological activity. The authors found that various Styrax species contain lignans and terpenoids with cytotoxic, acetylcholinesterase-inhibitory, antioxidant, and antifungal effects. Oleanolic acid from S. tonkinensis showed antiproliferative effects on HL-60 leukemia cells.

DOI
4

Successful Identification of the Species of Semipetrified Amber Medicinal Resin Benzoin Using Molecular Diagnostic Technology (Laboratory Study, 2023)

Feng J, He Q, Xie A, Liu Y. Scientific Reports, 2023, 13(1): 2943.

Researchers successfully extracted DNA from benzoin resin samples and used molecular diagnostic techniques (ITS2 sequencing) to identify the source species. Commercially available benzoin was found to derive from Styrax tonkinensis and, unexpectedly, Styrax japonicus. About 29.6% of samples were mixed with plant tissues from other genera, highlighting quality control concerns.

DOI

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.