What patterns does San Leng address?

San Leng addresses these TCM patterns of disharmony: Blood Stasis, Qi Stagnation, Blood Stagnation.

What conditions is San Leng used for?

San Leng is commonly used for: Uterine Fibroids, Amenorrhea, Amenorrhea, Ovarian Cysts, Hepatomegaly, Chronic Hepatitis, Abdominal Pain, Indigestion, Endometriosis. A TCM practitioner would consider this herb when these conditions arise from the specific patterns it addresses.

Herb Tuber (块茎 kuài jīng / 块根 kuài gēn)

San Leng

Q: What are the TCM actions of San Leng?

The TCM actions of San Leng include: Breaks Blood and Dispels Stasis, Moves Qi, Disperses Accumulations and Dissipates Nodules, Alleviates Pain.

Sparganium rhizome · 三棱

Sparganium stoloniferum Buch.-Ham. · Rhizoma Sparganii

Also known as: Jīng Sān Léng (京三棱), Hēi Sān Léng (黑三棱), Guāng Sān Léng (光三棱), Hóng Pú Gēn (红蒲根), Common Burreed Rhizome, Bur-Reed Rhizome, Sparganium

Images shown are for educational purposes only

San Leng is a powerful Blood-moving herb used to break up stubborn masses, lumps, and accumulations in the body. It is commonly used for conditions involving abdominal masses, severe menstrual pain with clotting, and chronic digestive stagnation. Because of its strong action, it is usually combined with supporting herbs and is not suitable during pregnancy.

Category Blood-invigorating and stasis-dispelling herbs (活血化瘀药) Blood-breaking and mass-dispersing herbs (破血消癥药)

Therapeutic focus Reproductive Health Digestive Health Circulation Support Pain Management

TCM Properties

Temperature

Neutral

Taste

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

Channels entered

Liver, Spleen

Parts used

Tuber (块茎 kuài jīng / 块根 kuài gēn)

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 San Leng does in the body, explained in both everyday and TCM terms

Therapeutic focus

In practical terms, San Leng is primarily used to support these areas of health:

Reproductive Health Digestive Health Circulation Support Pain Management

TCM Actions

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

Breaks Blood and Dispels Stasis Moves Qi Disperses Accumulations and Dissipates Nodules Alleviates Pain

How these actions work

'Breaks up Blood stasis' (破血行气) is San Leng's primary and most powerful action. Unlike gentler Blood-moving herbs, San Leng is classified as a 'Blood-breaking' herb, meaning it forcefully disperses long-standing Blood stasis that has already formed into palpable masses or lumps. Its pungent taste scatters and disperses, while its bitter taste drives downward, directing the herb into the Liver's Blood level where it clears old, stagnant Blood. This is used for abdominal masses (called zheng jia in TCM), severe menstrual pain with clotting, or amenorrhea caused by Blood stasis.

'Moves Qi' is the companion action to its Blood-breaking effect. In TCM, Blood and Qi always move together, so when Qi stagnates, Blood also stagnates. San Leng enters the Spleen channel and the Qi level, where it unblocks stagnant Qi in the abdomen and flanks. Wang Haogu, a noted classical physician, described it as a herb that "breaks Qi within the Blood." This dual action on both Blood and Qi makes it especially effective for conditions where stagnation has become deeply entrenched.

'Disperses accumulations and masses' refers to San Leng's ability to break down hardened lumps and masses in the abdomen, whether caused by Blood stasis or food stagnation. When food accumulates and fails to move through the digestive tract, San Leng can help clear the blockage. It enters the Spleen channel, where it assists in resolving food stagnation that causes epigastric and abdominal distension and pain.

'Relieves pain' follows naturally from its ability to restore the free flow of Qi and Blood. In TCM, the classic teaching is "where there is blockage, there is pain." By powerfully moving both Qi and Blood, San Leng relieves the stabbing, fixed pain that characterizes Blood stasis, as well as the distending pain of Qi stagnation in the chest, flanks, and abdomen.

Patterns Addressed

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

Why San Leng addresses this pattern

San Leng is one of the strongest herbs for treating Blood Stasis that has solidified into palpable masses. Its pungent taste disperses congealed Blood, while its bitter taste drives stagnation out of the Liver's Blood level. Unlike milder Blood-moving herbs that gently circulate, San Leng forcefully 'breaks' long-standing stasis. Zhang Xichun described it as "a key medicine for transforming stasis Blood." Its neutral temperature means it can be used in Blood Stasis patterns regardless of whether they lean Hot or Cold, making it versatile in combination with warming or cooling herbs as needed.

A practitioner would look for one or more of these signs

Amenorrhea

Caused by Blood stasis with lower abdominal masses

Amenorrhea

Fixed, stabbing pain with dark clots

Uterine Fibroids

Abdominal masses from chronic Blood stasis

Abdominal Pain

Fixed location, worse with pressure

Why San Leng addresses this pattern

San Leng addresses both sides of the Qi-Blood stagnation cycle. It enters the Liver and Spleen channels, targeting the two organs most responsible for the free flow of Qi and Blood in the abdomen. When Liver Qi stagnation leads to Blood stasis in the flanks and lower abdomen, or when Spleen Qi stagnation causes food to accumulate and block circulation, San Leng simultaneously moves the stagnant Qi and breaks through the congealed Blood. This dual action is why classical texts call it a 'Blood-level Qi herb' (血中气药). It is particularly suited for cases where long-standing Qi stagnation has progressed into palpable masses or lumps beneath the ribcage.

A practitioner would look for one or more of these signs

Abdominal Distention

Fullness and distension in the epigastric region and flanks

Abdominal Pain

Pain in the flanks or below the diaphragm, fixed in location

Hepatomegaly

Liver or spleen enlargement from chronic stagnation

Why San Leng addresses this pattern

Through its Spleen channel entry, San Leng can address severe food stagnation that causes bloating, distension, and abdominal pain. Its bitter and pungent tastes break through hardened accumulations in the digestive tract. This application is especially relevant when food stagnation has persisted long enough to create a sense of fullness and hardness in the abdomen, or when it combines with Qi stagnation. The raw form has strong Blood-breaking power, while the dry-fried form moderates this and enhances the food stagnation-resolving effect.

A practitioner would look for one or more of these signs

Abdominal Distention

Bloating and fullness after eating

Abdominal Pain

Epigastric and abdominal pain from overeating

Indigestion

Chronic food accumulation with hardness in the abdomen

Commonly Used For

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

Arises from: Blood Stasis Qi Stagnation

TCM Interpretation

In TCM, uterine fibroids are classified as zheng jia (accumulations and masses), understood as the end-stage result of prolonged Blood stasis in the uterus. The Liver governs the smooth flow of Blood and is closely connected to the uterus. When Liver Qi stagnates due to emotional stress or other factors, Blood gradually congeals and solidifies into palpable masses. Contributing factors can include Cold in the uterus that congeals Blood, Phlegm-Dampness that combines with stasis, or chronic Qi Deficiency that fails to move Blood adequately. The pattern is almost always one of excess, though it may sit on a foundation of underlying deficiency in long-standing cases.

Why San Leng Helps

San Leng directly addresses the core pathomechanism of uterine fibroids by powerfully breaking up congealed Blood in the Liver channel and uterus. Its dual action on both Blood stasis and Qi stagnation targets both the proximate cause (solidified stasis) and the driving force (stagnant Qi) behind fibroid formation. A large-scale population study in Taiwan found that San Leng was the most commonly prescribed single herb for uterine fibroids, reflecting its central clinical importance. It is typically paired with E Zhu (Curcuma rhizome) to simultaneously break Blood and move Qi, and combined with softening herbs like turtle shell or oyster shell, along with Qi-tonifying herbs to prevent the strong stasis-breaking action from depleting normal Qi.

Also commonly used for

Amenorrhea

Due to Blood stasis with lower abdominal masses

Amenorrhea

Severe menstrual pain with dark clots and fixed location

Ovarian Cysts

Pelvic masses from Blood stasis accumulation

Hepatomegaly

Liver enlargement from chronic hepatitis or cirrhosis

Abdominal Pain

Fixed, stabbing pain from Blood stasis or food stagnation

Indigestion

Severe food stagnation with epigastric distension

Endometriosis

Pelvic Blood stasis with pain and masses

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

Liver Spleen

Parts Used

Tuber (块茎 kuài jīng / 块根 kuài gēn)

Dosage & Preparation

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

Standard dosage

4.5-10g

Maximum dosage

Up to 15-30g in cases of severe Blood stasis masses or tumours, but only under close practitioner supervision and combined with Qi-tonifying herbs such as Ren Shen, Huang Qi, or Dang Shen to prevent depletion.

Dosage notes

Use the lower range (4.5 to 6g) for mild Qi and Blood stagnation with food accumulation. Use moderate doses (6 to 10g) for dysmenorrhoea, amenorrhoea due to Blood stasis, and moderate abdominal masses. Higher doses (15 to 30g) may be used by experienced practitioners for severe Blood stasis conditions such as large abdominal masses or tumour treatment, but must be paired with Qi-tonifying herbs (Ren Shen, Huang Qi, Bai Zhu) to prevent depletion of the body's fundamental Qi. Vinegar-processed San Leng (Cu San Leng) is preferred when the primary goal is breaking Blood stasis and relieving pain, as vinegar processing enhances entry into the Blood level and strengthens the pain-relieving effect. When multiple Blood-invigorating herbs are used in the same formula, the dose of San Leng should be reduced accordingly to avoid excessive anticoagulant effect.

Preparation

San Leng tubers are very hard and dense. They require prolonged soaking (until about 60-70% softened) before they can be sliced. After soaking, they are kept covered to allow moisture to penetrate fully, then sliced thinly and dried. For vinegar processing (Cu San Leng), slices are stir-fried with rice vinegar (approximately 15-30 kg vinegar per 100 kg herb) until the colour darkens, which enhances Blood-moving and pain-relieving action. No special decoction handling is required for the prepared slices when used in a standard decoction.

Processing Methods

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

Processing method

San Leng slices are stir-fried with rice vinegar until the color deepens. The standard ratio is approximately 15-30 kg of vinegar per 100 kg of herb. Some traditional methods involve boiling the whole tubers in vinegar-water until partially cooked, then draining and slicing.

How it changes properties

Vinegar processing directs San Leng more strongly into the Blood level and the Liver channel (vinegar is said to 'enter the Liver'). It enhances the herb's ability to break up Blood stasis, disperse hardened masses, and relieve pain. Research shows that vinegar-processed San Leng has a significantly higher total flavonoid content (about 50% more than raw) and stronger anti-platelet aggregation activity than the raw form. The thermal nature remains neutral, but the action shifts more toward the Blood level.

When to use this form

This is the most commonly used processed form and is preferred for Blood stasis conditions such as amenorrhea, dysmenorrhea with clots, abdominal masses, hepatosplenomegaly, and any condition where stubborn Blood stasis needs to be forcefully broken. It is the standard form used in the Chinese Pharmacopoeia.

Common Herb Pairs

These ingredients are traditionally combined with San Leng for enhanced therapeutic effect

E Zhu 1:1 (equal doses, typically 6-10g each)

San Leng and E Zhu (Curcuma rhizome) are the most classical Blood-breaking herb pair in Chinese medicine. San Leng is stronger at breaking Blood stasis, while E Zhu is stronger at moving Qi. Together they create a synergistic effect that simultaneously attacks stagnation from both the Blood and Qi sides, each compensating for the other's relative weakness. This pairing is the foundation of most formulas for abdominal masses, fibroids, and chronic accumulations.

When to use: Any condition involving chronic Blood stasis with Qi stagnation that has formed into palpable masses, lumps, or hardened accumulations. Common in uterine fibroids, ovarian cysts, hepatosplenomegaly, and abdominal masses.

Dang Gui 1:1 (typically 9g each)

San Leng breaks up old, stagnant Blood while Dang Gui nourishes and generates new Blood. This combination ensures that breaking stasis does not leave the patient Blood-deficient. Dang Gui also gently moves Blood, supporting San Leng's stronger action without excessive force. The pairing embodies the principle of 'breaking stasis while supporting the normal.'

When to use: Blood stasis amenorrhea or dysmenorrhea in patients who also show signs of Blood deficiency such as a pale complexion, dizziness, or thin pulse. Also used in chronic hepatitis formulas.

Lai Fu Zi 1:1 (typically 9g each)

San Leng breaks through stagnant accumulations while Lai Fu Zi (radish seed) promotes digestive movement and descends Qi. Together they powerfully resolve food stagnation with abdominal distension and pain, combining San Leng's mass-dispersing action with Lai Fu Zi's ability to move stagnant food downward.

When to use: Severe food stagnation with abdominal distension, bloating, and pain from overeating or chronic indigestion.

Bie Jia San Leng 9g : Bie Jia 15-30g

San Leng forcefully breaks Blood stasis while Bie Jia (turtle shell) softens hardness, nourishes Yin, and gently dissolves masses. This pairing combines aggressive stasis-breaking with the 'softening the hard and dispersing accumulations' strategy, and Bie Jia's Yin-nourishing effect helps protect against the drying, depleting tendency of San Leng's strong action.

When to use: Chronic masses with underlying deficiency, such as long-standing hepatosplenomegaly, liver cirrhosis, or deeply rooted abdominal masses in patients who are also depleted.

Comparable Ingredients

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

San Leng vs E Zhu

San Leng and E Zhu are almost always used together and have very similar indications, but their relative strengths differ. San Leng is stronger at breaking Blood stasis, while E Zhu is stronger at moving Qi stagnation. As Zhang Xichun wrote: 'the Blood-transforming power of San Leng is superior to E Zhu, while the Qi-regulating power of E Zhu is superior to San Leng.' When Blood stasis is the dominant problem, San Leng should be the primary herb; when Qi stagnation dominates, emphasize E Zhu.

San Leng vs Shui Zhi

Both San Leng and Shui Zhi (leech) are strong Blood-breaking herbs that enter the Liver channel. However, Shui Zhi is even more powerful and specific for breaking Blood stasis, working purely in the Blood level. San Leng is more moderate in comparison and also moves Qi and resolves food stagnation, giving it broader applications. Shui Zhi is preferred for severe stroke-related stasis or deep vascular obstruction; San Leng is preferred when stasis coexists with Qi stagnation and digestive accumulation.

San Leng vs Tao Ren

Both herbs move Blood stasis, but their strength and scope differ significantly. Tao Ren (peach kernel) is a milder Blood-invigorating herb that also moistens the Intestines, making it suitable for wider use including in Blood stasis with constipation. San Leng is much stronger and specifically targets hardened masses and deep-seated accumulations. Tao Ren can be used more freely in Blood stasis formulas; San Leng is reserved for stubborn cases where masses have already formed.

Common Substitutes & Adulterants

Related species and common adulterations to be aware of when sourcing San Leng

The most common substitute and source of confusion is Jing San Leng (荆三棱), the tuber of the sedge Scirpus yagara (Cyperaceae family). Confusingly, the botanical name 'Hei San Leng' (Black San Leng) refers to the official Sparganium species, while the commercial product called 'Hei San Leng' is actually the sedge species. Key distinctions: authentic San Leng (Sparganium stoloniferum) has a yellowish-white surface when peeled, is very heavy and extremely hard to break, and produces a tingling sensation when chewed. The sedge substitute has a dark brown-black surface, is much lighter in weight (almost cork-like), floats in water, and lacks the numbing tongue sensation. It also does not contain starch granules on microscopy, unlike authentic San Leng. Other less common adulterants include Bian Gan Biao Cao (Scirpus planiculmis) from Henan and Jiangsu, and water chestnut (Fu Ci / Eleocharis dulcis), which historical sources warn was sometimes fraudulently passed off as San Leng.

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

Toxicity Classification

Classical Chinese pharmacopoeia toxicity rating for San Leng

Non-toxic

San Leng is classified as non-toxic in the Chinese Pharmacopoeia and in classical sources such as the Kai Bao Ben Cao (which states "tastebitter, neutral, non-toxic"). However, its strong Blood-breaking action means overuse or inappropriate use can lead to excessive bleeding, depletion of Qi and Blood, and weakened digestion. Pharmacological studies show it has significant anticoagulant effects (prolonging clotting time, inhibiting platelet aggregation), so high doses carry a risk of haemorrhagic complications. Vinegar processing (Cu San Leng) enhances its targeted Blood-moving action while the bran-fried form (Fu Chao San Leng) moderates its intensity. No specific toxic compounds have been identified, but caution with dosage is essential.

Contraindications

Situations where San Leng should not be used or requires extra caution

Avoid

Pregnancy. San Leng is a powerful Blood-breaking herb that can stimulate uterine contractions and has historically been noted to cause miscarriage. It is classified as a pregnancy-prohibited (禁用) herb, not merely cautioned.

Avoid

Active hemorrhage or profuse menstrual bleeding. San Leng's strong Blood-invigorating and anticoagulant actions can worsen active bleeding conditions.

Caution

Qi deficiency without Blood stasis. San Leng's vigorous breaking action can severely deplete Qi in already weakened patients. As the Yi Xue Qi Yuan (Medical Origins) states, it 'damages true Qi' and should not be used in Qi-deficient individuals. If used for masses in deficient patients, it must be combined with Qi-tonifying herbs like Ren Shen, Huang Qi, or Bai Zhu.

Caution

Blood deficiency with amenorrhea (blood depletion rather than Blood stasis). San Leng treats amenorrhea caused by stasis, not by insufficient Blood. Using it in Blood-deficient amenorrhea will further deplete Blood reserves.

Caution

Patients on anticoagulant or antiplatelet medications. San Leng has demonstrated significant anticoagulant and antiplatelet activity in pharmacological studies, which may compound the effects of pharmaceutical blood thinners.

Classical Incompatibilities

Traditional Chinese pharmacological incompatibilities — herbs or substances to avoid combining with San Leng

San Leng appears on the Nineteen Mutual Fears (十九畏) list: Ya Xiao (牙硝, a form of Mang Xiao / Glauber's salt, sodium sulphate) fears San Leng. The two should not be used together according to traditional compatibility restrictions.

Special Populations

Important considerations for pregnancy, breastfeeding, and pediatric use

Pregnancy

Contraindicated. San Leng is classified as a pregnancy-prohibited herb (妊娠禁用) in the Chinese Pharmacopoeia and major classical references. The Pin Hui Jing Yao states: "Must not be taken during pregnancy." The Ri Hua Zi Ben Cao explicitly notes that it "causes miscarriage" (落胎). Pharmacological research confirms that San Leng water decoction has an excitatory effect on isolated rabbit uterine smooth muscle, which explains the mechanism behind its traditional prohibition. Its vigorous Blood-breaking action poses a serious risk of uterine haemorrhage and threatened or induced miscarriage at any stage of pregnancy.

Breastfeeding

Not recommended during breastfeeding. San Leng is a potent Blood-breaking herb, and there is insufficient safety data regarding transfer of its active components (including flavonoids, phenylpropanoids, and volatile oils) through breast milk. Given its strong dispersing nature, it could theoretically deplete the mother's Qi and Blood, potentially reducing milk production. Nursing mothers should avoid this herb unless specifically prescribed by a qualified practitioner for a condition requiring its use, with careful monitoring.

Children

San Leng is a strong Blood-breaking herb and should generally be avoided in children. In rare cases where a paediatric condition specifically calls for breaking Blood stasis (such as certain abdominal masses), classical sources indicate substantially reduced doses based on the child's age and weight. For example, the Pu Ji Fang records a dose of approximately 1.5g for a three-year-old child. Any paediatric use should only be under close supervision by an experienced practitioner, and treatment duration should be kept as short as possible to protect the child's developing Qi and Blood.

Drug Interactions

If you are taking pharmaceutical medications, be aware of these potential interactions with San Leng

Anticoagulant and antiplatelet medications (e.g. warfarin, heparin, rivaroxaban, aspirin, clopidogrel): San Leng has well-documented anticoagulant and antiplatelet properties. Its active compound Sparstolonin B has been shown to prolong clotting time at concentrations comparable to rivaroxaban and to inhibit ADP-induced platelet aggregation. Concurrent use with pharmaceutical anticoagulants or antiplatelet agents may significantly increase the risk of bleeding. Close monitoring of coagulation parameters (INR, PT) is essential if co-administration is unavoidable.

Thrombolytic agents: The Blood-breaking action of San Leng may compound the effects of thrombolytic drugs, increasing haemorrhagic risk.

NSAIDs: Non-steroidal anti-inflammatory drugs also affect platelet function and gastric mucosal integrity. Combined use may increase the risk of gastrointestinal bleeding.

Dietary Advice

Foods and dietary considerations when taking San Leng

While taking San Leng, avoid excessively cold and raw foods, which can impede the circulation of Qi and Blood and work against the herb's dispersing action. Because San Leng strongly moves Blood and Qi, it is beneficial to include easily digestible, nourishing foods to support the Spleen and Stomach. Avoid excessive alcohol consumption, which can compound its Blood-moving effects and increase the risk of bleeding. If the formula also contains vinegar-processed San Leng, avoid excessive consumption of other acidic or vinegar-rich foods.

Botanical Description

Physical characteristics and morphology of the San Leng source plant

Sparganium stoloniferum Buch.-Ham. (family Sparganiaceae) is a perennial aquatic or marsh herb growing 50 to 100 cm tall. It produces creeping rhizomes that lie horizontally in the mud, with thick, short tubers forming beneath them. The stem is upright, cylindrical, and smooth.

The leaves are linear, arranged in two rows, 60 to 95 cm long and about 2 cm wide, tapering to a point at the tip with a prominent midrib on the underside. Flower stalks emerge from the leaf clusters, sometimes branching. The plant is monoecious, bearing separate male and female flowers clustered into spherical heads with leafy bracts. Male flower heads (usually 2 to 10) sit above the female heads (usually 1 to 3). Fruits form dense, spiky globular clusters about 2 cm in diameter, with small obovate-conical drupes. Flowering occurs from June to July, with fruiting from July to August.

The plant grows naturally in ponds, marshes, shallow waterways, and wet ditches throughout temperate East Asia, including China, Japan, and Korea.

Sourcing & Harvesting

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

Harvesting season

Winter through to the following spring (typically November to March). The tubers are dug up, cleaned, the outer skin is peeled off, and they are dried in the sun.

Primary growing regions

Jiangsu, Henan, Shandong, Jiangxi, and Anhui provinces are the primary production regions. Zhejiang province is noted for producing superior quality San Leng that meets or exceeds pharmacopoeia standards. The plant also grows in Liaoning, Heilongjiang, Jilin, Hubei, Sichuan, and other provinces with suitable wetland habitats. It favours ponds, marshes, shallow water ditches, and wet lowland areas across eastern and northern China.

Quality indicators

Good quality San Leng tubers are conical or slightly flattened obovate in shape, 2 to 6 cm long and 2 to 4 cm in diameter. The surface should be yellowish-white or greyish-yellow (indicating the outer skin has been properly peeled) with visible knife-scraping marks and fine, dot-like root scars arranged in roughly horizontal rings. The tuber should feel heavy and very firm and solid, extremely difficult to break. Cross-sections should be pale yellowish-white. The odour is faint, the taste bland, and chewing should produce a subtle tingling-numbing sensation on the tongue. Reject tubers that are light in weight, spongy, or have a dark brown to black surface (these may be the sedge substitute Scirpus yagara rather than authentic Sparganium stoloniferum).

Classical Texts

Key passages from the classical Chinese medical texts that describe San Leng and its therapeutic uses

《开宝本草》(Kai Bao Ben Cao)

Original: 主老癖症瘕结块。
Translation: "It principally treats chronic accumulations, abdominal masses, and hardened lumps."

《医学启源》(Yi Xue Qi Yuan) — Zhang Yuansu

Original: 主心膈痛，饮食不消，破气。破气损真，气虚人不用。
Translation: "It principally treats pain in the chest and diaphragm, undigested food, and breaks stagnant Qi. It damages true Qi, so those with Qi deficiency should not use it."

Wang Haogu (王好古)

Original: 三棱，破血中之气，肝经血分药也。三棱、莪术治积块疮硬者，乃坚者削之也。
Translation: "San Leng breaks the Qi within the Blood and is a Liver channel Blood-level herb. When San Leng and E Zhu treat hardened masses and firm swellings, this is the principle of paring away what is hard."

《本草纲目》(Ben Cao Gang Mu) — Li Shizhen

Original: 三棱能破气散结，故能治诸病，其功可近于香附而力峻，故难久服。
Translation: "San Leng can break Qi and disperse knotted accumulations, and thus treats many diseases. Its function approaches that of Xiang Fu but its action is more drastic, so it is difficult to take for prolonged periods."

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

Original: 三棱气味俱淡，微有辛意……性皆微温，为化瘀血之要药。以治男子痃癖，女子症瘕，月经不通，性非猛烈而建功甚速。……若细核二药之区别，化血之力三棱优于莪术，理气之力莪术优于三棱。
Translation: "San Leng's flavour and aroma are both bland with a slight pungency... both [San Leng and E Zhu] are slightly warm in nature and are essential herbs for transforming Blood stasis. They treat masses in men and abdominal lumps in women, and amenorrhea. Their nature is not violent yet they achieve results swiftly... If one examines the distinction between these two herbs closely, San Leng is superior to E Zhu in transforming Blood stasis, while E Zhu is superior to San Leng in regulating Qi."

《本草经疏》(Ben Cao Jing Shu)

Original: 三棱，从血药则治血，从气药则治气。……苦能泄而辛能散，甘能和而入脾，血属阴而有形，此所以能治一切凝结停滞有形之坚积也。……故凡用以消导，必资人参、芍药、地黄之力，而后可以无弊。
Translation: "San Leng, when combined with Blood herbs treats Blood disorders, and when combined with Qi herbs treats Qi disorders... Its bitterness drains, its pungency disperses, its sweetness harmonizes and enters the Spleen. Blood is Yin and has form; this is why it can treat all solidified, stagnant, tangible hard accumulations... Therefore, whenever it is used for dispersing and guiding, one must rely on the strength of Ren Shen, Shao Yao, and Di Huang to avoid harm."

Historical Context

The history and evolution of San Leng's use in Chinese medicine over the centuries

San Leng was first recorded as a medicinal herb in the Ben Cao Shi Yi (Supplement to the Materia Medica) by Chen Cangqi during the Tang Dynasty (739 CE). Its name "San Leng" (三棱, "Three Edges") refers to the sharply three-angled stem of the original plant source (the sedge Scirpus yagara). Over time, there has been considerable botanical confusion: the Ben Cao Tu Jing (Illustrated Classic of Materia Medica) described three forms based on tuber shape (flat like a crucian carp, round like a dark plum, or hooked like a chicken's claw), noting that "all three are one substance, differing only in the strength of their action." The Chinese Pharmacopoeia now designates the Sparganiaceae species Sparganium stoloniferum (known as "Hei San Leng" botanically) as the official source, while the sedge family species (Scirpus yagara, confusingly called "Jing San Leng" in commerce) is a commonly encountered substitute.

San Leng has long been inseparable from its classic partner herb E Zhu (Curcumae Rhizoma). Zhang Xichun, the influential late Qing to early Republican era physician, famously distinguished the pair: San Leng excels at transforming Blood stasis, while E Zhu excels at moving Qi. Li Dongyuan (Li Gao) of the Jin-Yuan period notably included Ren Shen in his formulas containing San Leng, reflecting the important principle that strong dispersing herbs must be paired with tonifying agents to protect the body's foundational Qi. Li Shizhen compared San Leng's function to Xiang Fu (Cyperus) but warned it was more drastic and unsuitable for prolonged use.

Modern Research

3 published studies investigating the pharmacological effects or clinical outcomes of San Leng

Comprehensive review of traditional clinical application, processing, phytochemistry, pharmacology, and toxicity of Sparganii Rhizoma (2021)

Sun Y, et al. Journal of Ethnopharmacology, 2021, 268, 113571.

This systematic review compiled evidence from multiple databases on San Leng's traditional uses, chemical constituents, and modern pharmacology. It found that San Leng has significant bioactivities including anti-tumour, antithrombotic, and oestrogen-antagonistic effects. Key chemical constituents include phenylpropanoids, flavonoids, alkaloids, organic acids, and volatile oils. The herb is predominantly used in gynaecological conditions such as uterine fibroids, ovarian cysts, endometriosis, and dysmenorrhoea.

PubMed

Inhibition of factor Xa activity, platelet aggregation, and experimentally induced thrombosis by Sparstolonin B (2022)

Wang Y, et al. PubMed, 2022.

This study investigated Sparstolonin B (SsnB), an isocumarin compound from Sparganium stoloniferum, for antithrombotic activity. SsnB prolonged clotting time at concentrations comparable to the anticoagulant rivaroxaban and inhibited ADP-induced and U46619-induced platelet aggregation. It also inhibited phosphorylation of PLCgamma2/PKC pathways and intracellular calcium mobilization in platelets, demonstrating clear anticoagulant and antiplatelet mechanisms.

PubMed

Phenylpropanoids from Sparganium stoloniferum and their antiplatelet aggregation activities (2023)

Journal of Asian Natural Products Research, 2023, 25(7).

Four new ferulic acid sucrose esters and four known phenylpropanoids were isolated from San Leng rhizome. All eight compounds exhibited obvious inhibitory effects on ADP-induced platelet aggregation, supporting the herb's traditional use for breaking Blood stasis and providing a molecular basis for its anticoagulant activity.

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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.