Herb Rhizome (根茎 gēn jīng)

Lu Gen

Reed rhizome · 芦根

Phragmites communis Trin. · Rhizoma Phragmitis

Also known as: Phragmites root, Common reed rhizome, Wěi Gēn (苇根),

Lu Gen (Reed rhizome) plant

Images shown are for educational purposes only

Reed rhizome is a gentle cooling herb commonly used in Chinese medicine to clear Heat from the Lungs and Stomach. It helps relieve fever-related thirst and dry mouth, calms nausea and vomiting, and supports healthy urination. Because it moistens without being heavy, it is especially valued during feverish illnesses where the body's fluids have been depleted.

Category Heat-clearing herbs Herbs that clear Heat and drain Fire (清热泻火药)
Therapeutic focus Fever Relief Respiratory Health Digestive Health Urinary Health

TCM Properties

Temperature

Cold

Taste

Sweet (甘 gān)

Channels entered

Lungs, Stomach

Parts used

Rhizome (根茎 gēn jīng)

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What This Herb Does

Every herb has a specific set of actions — here's what Lu Gen does in the body, explained in both everyday and TCM terms

Therapeutic focus

In practical terms, Lu Gen is primarily used to support these areas of health:

Fever Relief Respiratory Health Digestive Health Urinary Health

TCM Actions

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

Clears Heat and Drains Fire Generates Fluids and Relieves Thirst Eliminates Irritability Stops Vomiting Promotes Urination Expels Phlegm and Discharges Pus Vents Rashes

How these actions work

'Clears Heat and drains Fire' refers to Lu Gen's ability to cool internal Heat, especially in the Lung and Stomach. Because it is sweet and cold, it gently clears excess Heat from these organs without being overly harsh. This makes it useful for fevers, restlessness, and thirst caused by Heat in the body's middle and upper regions.

'Generates fluids and relieves thirst' means Lu Gen helps the body produce and preserve its natural moisture. Its sweet taste nourishes fluids while its cold nature clears the Heat that was drying them up. This is why it is widely used in warm-febrile illnesses (Wen Bing) where high fever has depleted body fluids, causing intense thirst and dry mouth. A key advantage of Lu Gen is that it moistens without being heavy or sticky, so it replenishes fluids without trapping pathogenic Heat inside the body.

'Stops vomiting' means Lu Gen can settle the Stomach when Heat causes it to rebel upward. Stomach Heat disrupts the normal downward movement of digestion, leading to nausea, vomiting, or hiccups. Lu Gen clears that Heat and restores the Stomach's natural descending function. It is often paired with Zhu Ru (Bamboo Shavings) for this purpose.

'Promotes urination' means Lu Gen gently encourages fluid movement downward and out through the urinary system. This is helpful when Heat concentrates in the Bladder, causing dark, scanty, or painful urination. It is often combined with Bai Mao Gen (Imperata root) or Che Qian Zi (Plantain seed) for urinary Heat conditions.

'Clears Lung Heat and expels phlegm to discharge pus' describes Lu Gen's particular affinity for the Lungs. When Heat lodges in the Lungs, it can cause cough with thick yellow phlegm, or in severe cases, a lung abscess (Fei Yong) with foul-smelling pus. Lu Gen clears this Heat, thins the phlegm, and helps the body expel infected material. This is the basis for its prominent role in Wei Jing Tang (Reed Decoction).

'Encourages the expression of rashes' means that during febrile illnesses where a rash should appear but is incompletely expressed, Lu Gen can help bring it to the surface. In TCM, an incomplete rash during measles or other eruptive fevers suggests the pathogen is trapped inside. Lu Gen's light, ascending nature helps vent the Heat outward through the skin.

Patterns Addressed

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

Why Lu Gen addresses this pattern

Lu Gen enters the Lung channel and is sweet and cold, making it well suited to clear Heat that has lodged in the Lungs. Its cold nature directly opposes Lung Heat, while its sweet, fluid-rich quality moistens the Lungs and helps thin thick, sticky phlegm. In cases of Lung Heat progressing to lung abscess (Fei Yong), Lu Gen clears the Heat, promotes the discharge of pus, and nourishes Lung Yin that has been damaged by the Heat. This is why it serves as the King herb in Wei Jing Tang.

A practitioner would look for one or more of these signs

Hypochondrial Pain That Is Worse On Coughing And Breathing

Cough with thick yellow phlegm

Fever

Fever with restlessness

Dry Mouth

Dry mouth and thirst

Chest Pain

Chest pain with foul-smelling sputum in lung abscess

Commonly Used For

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

Arises from: Lung Heat

TCM Interpretation

TCM views pneumonia, particularly when it progresses to lung abscess, as a condition where Heat toxins invade the Lungs and combine with phlegm and stagnant Blood. This creates an internal 'abscess' (Fei Yong). The Heat causes the Lung tissue to become inflamed and corrupted, producing foul-smelling, purulent sputum. The pathomechanism involves Heat congesting the Lung network vessels, obstructing the normal clearing and descending function of the Lungs, and eventually causing tissue breakdown.

Why Lu Gen Helps

Lu Gen is sweet, cold, and enters the Lung channel, making it a primary herb for clearing Lung Heat. Its hollow, tube-like physical structure was traditionally seen as having an affinity for opening the Lung passageways. It clears Heat from the Lung, helps thin and expel purulent sputum, and simultaneously nourishes the Lung fluids that Heat has damaged. In the classical formula Wei Jing Tang (Reed Decoction), Lu Gen serves as the King herb, working with Dong Gua Ren (winter melon seed) and Yi Yi Ren (Job's tears) to clear Heat, resolve phlegm, and discharge pus from the Lungs.

Also commonly used for

Hypochondrial Pain That Is Worse On Coughing And Breathing

Cough from Lung Heat with thick yellow phlegm

Thirst

Excessive thirst from Heat consuming body fluids

Bronchitis

Acute or chronic bronchitis with Heat pattern

Urinary Tract Infection

Hot, painful, dark-coloured urination

Measles

Incomplete expression of rash in measles

Gastritis

Stomach inflammation with Heat signs

Herb Properties

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

Temperature

Cold

Taste

Sweet (甘 gān)

Channels Entered

Lungs Stomach

Parts Used

Rhizome (根茎 gēn jīng)

Dosage & Preparation

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

Standard dosage

15-30g (dried); fresh product double the dose, or juice the fresh rhizome

Maximum dosage

Up to 60g of dried product (or equivalent fresh product) when used to promote rash eruption or in acute febrile conditions, under practitioner guidance

Dosage notes

Fresh Lu Gen (鲜芦根) is preferred over the dried form for generating fluids and clearing Heat, as its juice content is much higher and its cooling, fluid-nourishing action is stronger. When using fresh product, the dosage is generally double that of the dried (30 to 60g or more). For mild Heat with thirst, standard doses of 15 to 30g dried are sufficient. For lung abscess (肺痈) patterns, larger doses are used, often combined with Yi Yi Ren, Dong Gua Ren, and Tao Ren in formulas like Wei Jing Tang. When used specifically to promote rash eruption in children, doses up to 60g may be employed. Fresh rhizome can also be juiced directly and taken as a beverage.

Preparation

No special decoction handling required. Lu Gen is simply added to the decoction with the other herbs and boiled normally. Fresh rhizome should have its nodes and fibrous roots removed before use. When using fresh Lu Gen for its juice, it can be crushed and the juice pressed out, then taken directly or mixed into the strained decoction.

Common Herb Pairs

These ingredients are traditionally combined with Lu Gen for enhanced therapeutic effect

Zhu Ru
Zhu Ru 1:1 (Lu Gen 30g : Zhu Ru 10-15g, with Lu Gen in larger absolute dose due to its milder potency)

Both Lu Gen and Zhu Ru clear Heat from the Lung and Stomach and stop vomiting. Lu Gen excels at generating fluids while Zhu Ru is stronger at transforming phlegm. Together, they clear Stomach Heat, calm nausea, and resolve phlegm more effectively than either herb alone.

When to use: Stomach Heat causing nausea, vomiting, or hiccups, especially when accompanied by thirst and phlegm. Classical use seen in Lu Gen Yin Zi (Reed Rhizome Drink) from Qian Jin Fang.

Tian Men Dong
Tian Men Dong 1:1 (Lu Gen 30g : Mai Men Dong 15g)

Both herbs generate fluids and moisten dryness. Mai Men Dong nourishes Yin and moistens the Lungs and Stomach more deeply, while Lu Gen clears Heat and generates fluids without being cloying. Together, they provide stronger fluid replenishment and Heat-clearing than either alone.

When to use: Warm-febrile diseases that have damaged body fluids, causing intense thirst, dry mouth, and restlessness. Also used for Lung dryness with cough.

Bai Mao Gen
Bai Mao Gen 1:1 (Lu Gen 30g : Bai Mao Gen 30g)

Both are sweet, cold herbs that clear Heat and promote urination. Bai Mao Gen (Imperata root) also cools the Blood and stops bleeding, while Lu Gen focuses more on generating fluids and clearing Lung and Stomach Heat. Together, they powerfully clear Heat and promote fluid metabolism via the urinary tract.

When to use: Heat-type urinary difficulty with dark, scanty, or painful urination. Also for acute nephritis or early-stage edema with Heat signs. Classical sources note that when fresh Bai Mao Gen is unavailable, fresh Lu Gen can substitute.

Dong Gua Zi
Dong Gua Zi 2:1 (Lu Gen 60g : Dong Gua Ren 30g)

Lu Gen clears Lung Heat and helps discharge pus, while Dong Gua Ren (winter melon seed) clears Heat, transforms phlegm, and promotes the drainage of pus. Together, they form the core pair in Wei Jing Tang for treating lung abscess, combining Heat-clearing with phlegm and pus expulsion.

When to use: Lung abscess (Fei Yong) with cough, chest pain, and foul-smelling purulent sputum. Also for phlegm-Heat cough with thick, difficult-to-expectorate phlegm.

Key Formulas

These well-known formulas feature Lu Gen in a prominent role

Wei Jing Tang 苇茎汤 King

The definitive formula for lung abscess (Fei Yong) from the Qian Jin Fang. Lu Gen (as reed stem/rhizome) serves as King at a large dose of 60g, showcasing its core ability to clear Lung Heat, open the Lung passageways, and promote the discharge of pus. This formula best demonstrates Lu Gen's affinity for the Lungs in treating Heat-phlegm and abscess conditions.

Sang Ju Yin 桑菊飲 Assistant

Wu Jutong's 'mildly cool and light formula' from the Wen Bing Tiao Bian for early-stage Wind-Heat cough. Lu Gen serves as Assistant, using its fluid-generating and gentle Heat-clearing action to support the formula's Wind-Heat dispersal while protecting body fluids from damage. Showcases Lu Gen's role as a supportive herb in Wen Bing prescriptions.

Yin Qiao San 銀翹散 Assistant

Wu Jutong's 'moderately cool formula' from the Wen Bing Tiao Bian for early Wind-Heat invasion with fever, sore throat, and thirst. Lu Gen (as Xian Wei Gen, fresh reed root) generates fluids and gently clears Heat, embodying the Wen Bing school's emphasis on protecting Yin fluids even during the earliest stages of febrile disease.

Comparable Ingredients

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

Tian Hua Fen
Lu Gen vs Tian Hua Fen

Both are sweet, cold herbs that clear Heat and generate fluids. However, Tian Hua Fen (Trichosanthes root) is more potent at generating fluids and is specifically indicated for Lung dryness, wasting-thirst (Xiao Ke), and draining pus from sores. Lu Gen is milder and lighter in action, better suited as a supporting herb in febrile illnesses where its non-cloying nature is an advantage. Lu Gen also stops vomiting and promotes urination, which Tian Hua Fen does not.

Zhi Mu
Lu Gen vs Zhi Mu

Both clear Heat and generate fluids, but Zhi Mu (Anemarrhena) is a much stronger Heat-clearing herb that clears blazing Stomach Fire and Lung Heat forcefully, and also nourishes Kidney Yin. Lu Gen is far milder and acts as a gentle supporting herb. Lu Gen is preferred when the primary goal is gentle fluid-generation without heavy cold, or when stopping vomiting is needed. Zhi Mu is chosen for more intense Heat patterns requiring stronger intervention.

Bai Mao Gen
Lu Gen vs Bai Mao Gen

Both are sweet, cold, and promote urination. The key difference is that Bai Mao Gen (Imperata root) cools the Blood and stops bleeding, making it essential for blood in the urine (hematuria) and nosebleeds, while Lu Gen focuses on Lung and Stomach Heat, stops vomiting, and expels pus from lung abscesses. Classical texts note they can substitute for each other when one is unavailable.

Common Substitutes & Adulterants

Related species and common adulterations to be aware of when sourcing Lu Gen

The most common adulterant is the rhizome of Zizania caduciflora (茭白根, water bamboo root). It can be distinguished from authentic Lu Gen because it has a smaller diameter (0.6 to 0.8 cm vs. 1 to 2 cm), a brownish-yellow to golden surface colour, thinner walls without the characteristic ring of small pores visible on cross-section, outer bark that does not peel away easily, and a bland taste lacking the sweet flavour of genuine Lu Gen. Additionally, the aboveground stem of reed (Wei Jing, 苇茎) is sometimes sold in place of the rhizome. While functionally similar, Wei Jing has slightly different clinical emphasis (more focused on clearing Lung Heat and expelling pus) compared to Lu Gen (stronger at generating fluids and stopping thirst).

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

Toxicity Classification

Classical Chinese pharmacopoeia toxicity rating for Lu Gen

Non-toxic

Lu Gen is classified as non-toxic in both classical and modern sources. The Yao Xing Lun (药性论) explicitly states it is "wu du" (无毒, non-toxic). No toxic components have been identified. A 2019 genotoxicity study found no mutagenic or genotoxic effects from aqueous reed rhizome extract in standard in vitro and in vivo test batteries. The only concern with excessive or prolonged use is damage to Yang Qi due to its cold nature, which may manifest as fatigue, poor appetite, or loose stools. These are functional effects of overcooling, not toxicity in the pharmacological sense.

Contraindications

Situations where Lu Gen should not be used or requires extra caution

Caution

Spleen and Stomach deficiency-Cold (脾胃虚寒). Lu Gen is sweet and cold in nature. People with weak, cold digestive systems who tend toward loose stools, poor appetite, or abdominal coldness should avoid this herb, as it can further damage Spleen and Stomach Yang.

Avoid

Vomiting or abdominal distension caused by Cold. The Ben Cao Jing Shu (本草经疏) specifically warns against using Lu Gen when vomiting or cholera-like symptoms are caused by Cold pathogen rather than Heat, as its cold nature would worsen the condition.

Caution

Prolonged high-dose use. Long-term or excessive use of this cold herb can injure Yang Qi, potentially leading to fatigue, reduced appetite, and loose stools.

Special Populations

Important considerations for pregnancy, breastfeeding, and pediatric use

Pregnancy

Generally considered safe at standard doses during pregnancy. Classical texts actually note Lu Gen's use for pregnant women. The Ri Hua Zi Ben Cao (日华子本草) records that it "treats pregnant women's heart heat" (好孕人心热), and the Ben Cao Jing Shu explains that "pregnant women with insufficient blood develop heart heat; its sweet, cold nature clears heat and settles the stomach." It has no known uterine-stimulating or blood-moving properties. However, as with all cold-natured herbs, prolonged heavy use should be avoided in pregnancy, particularly if the person has a cold constitution.

Breastfeeding

No specific contraindications for breastfeeding have been identified. Lu Gen is a mild, food-grade herb with sweet flavour and no known toxic components. Its cold nature means very high doses over long periods could theoretically affect milk production in mothers with underlying Spleen-Stomach Yang deficiency, but at standard doses it is generally regarded as safe during breastfeeding.

Children

Lu Gen is considered a mild, non-toxic herb suitable for children. Dosage should be reduced proportionally based on age and body weight, typically one-third to one-half of adult dosage for young children. It is often included in pediatric formulas for childhood febrile illness with thirst and irritability, and for promoting the eruption of rashes (such as measles) when they fail to surface properly. Its sweet taste and gentle action make it well-tolerated by children.

Drug Interactions

If you are taking pharmaceutical medications, be aware of these potential interactions with Lu Gen

No well-documented pharmacological drug interactions have been reported for Lu Gen. Its known active constituents include polysaccharides, asparagine, coixol, ferulic acid, p-coumaric acid, and B vitamins. Pharmacological research has demonstrated mild sedative, analgesic, and blood sugar-lowering effects. Based on these properties:

  • People taking hypoglycemic medications should be aware of the herb's mild blood sugar-lowering activity, though clinically significant interaction at standard doses is unlikely.
  • The mild sedative action observed in animal studies suggests theoretical caution when combined with central nervous system depressants, though this has not been confirmed clinically.

Overall, Lu Gen is pharmacologically mild and no clinically significant drug interactions have been established in the literature.

Dietary Advice

Foods and dietary considerations when taking Lu Gen

When taking Lu Gen for Heat-related conditions, it is best to avoid hot, spicy, greasy, or deep-fried foods, which can generate further internal Heat and counteract the herb's cooling effect. Light, easily digestible foods such as congee, pear, watermelon, and mung bean soup complement its fluid-generating and Heat-clearing actions. Because Lu Gen is cold in nature, people with weak digestion should not combine it with excessive amounts of raw or cold foods to avoid further burdening the Spleen and Stomach.

Botanical Description

Physical characteristics and morphology of the Lu Gen source plant

Phragmites communis Trin. (synonym Phragmites australis (Cav.) Trin. ex Steud.), commonly known as common reed, is a tall perennial grass of the family Poaceae. The plant grows 2 to 5 meters tall with upright, hollow stems that often have a whitish powder coating below the nodes. Leaves are arranged in two rows, flat and lance-shaped, 30 to 60 cm long and 2 to 5 cm wide, grey-green to blue-green in colour, with rough margins. Large, plume-like flower panicles appear at the top of the stems from September to October, measuring 20 to 40 cm long, typically purplish-brown to yellowish. The underground rhizome system is thick, creeping horizontally, and hollow at the nodes, with buds at each node.

Reeds thrive in warm, moist environments and are cold-hardy. They grow abundantly along rivers, lakes, marshes, ponds, and ditches in shallow water or wet soil. The medicinal part is the fresh or dried rhizome (underground stem), which is cylindrical, 1 to 2 cm in diameter, yellowish-white with a glossy surface, hollow in the centre, and sweet-tasting.

Sourcing & Harvesting

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

Harvesting season

Can be harvested year-round; traditionally preferred in late spring, early summer, or autumn. Fresh rhizome (鲜芦根) is clinically preferred over the dried form.

Primary growing regions

Lu Gen is produced throughout most provinces of China, as the common reed (Phragmites communis) grows widely in wetlands, rivers, lakes, and marshes nationwide. It is not strongly associated with a single dao di (terroir) region the way many herbs are. Major producing areas include Anhui, Jiangsu, Zhejiang, and Hubei provinces. Because the plant is so widespread and abundant, it is typically wild-harvested rather than cultivated. Fresh Lu Gen is preferred in clinical use, and proximity to clean water sources is considered important for quality.

Quality indicators

Good quality Lu Gen (both fresh and dried) should have thick, uniform cylindrical segments with a yellowish-white colour and a natural glossy sheen on the surface. The outer bark should be slightly loose and peelable. Nodes should be clearly visible as ring-shaped bands. The cross-section should be hollow, with a wall thickness of about 1 to 2 mm and small pores arranged in a ring pattern. The herb should feel light in weight but tough and not easily broken. It should have a faint, clean smell and a distinctly sweet taste. Avoid pieces that are thin, dark-coloured, overly fibrous, or have excessive attached rootlets. For dried Lu Gen, the segments become somewhat flattened, with longitudinal wrinkles between nodes. Fresh Lu Gen is clinically preferred and should appear moist, plump, and juicy.

Classical Texts

Key passages from the classical Chinese medical texts that describe Lu Gen and its therapeutic uses

Ming Yi Bie Lu (名医别录) by Tao Hongjing, ~500 CE

Original: 主消渴客热，止小便利。

Translation: "Treats wasting-thirst [excessive thirst from internal heat] and visiting Heat; stops excessive urination."

Yao Xing Lun (药性论)

Original: 能解大热，开胃。治噎哕不止。

Translation: "Able to resolve great Heat, open the Stomach. Treats incessant hiccup and retching."

Tang Ben Cao (唐本草)

Original: 疗呕逆不下食、胃中热、伤寒患者弥良。

Translation: "Treats vomiting, inability to take food, Stomach Heat. Especially good for patients with Cold Damage [febrile] diseases."

Ben Cao Jing Shu (本草经疏) by Miu Xiyong

Original: 芦根，味甘寒而无毒。甘能益胃和中，寒能除热降火，热解胃和，则津液流通而渴止矣。

Translation: "Lu Gen is sweet, cold, and non-toxic. Its sweetness benefits the Stomach and harmonizes the middle; its coldness clears Heat and descends fire. When Heat is resolved and the Stomach harmonized, fluids flow freely and thirst stops."

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

Original (excerpt): 苇之根居于水底，其性凉而善升……其性凉能清肺热，中空能理肺气，而又味甘多液，更善滋养肺阴，则用根实胜于茎明矣。

Translation: "The root of the reed dwells at the bottom of the water; its nature is cool and it is good at ascending... Its cool nature can clear Lung Heat, its hollow form can regulate Lung Qi, and its sweet, juicy flavour excels at nourishing Lung Yin. Thus the root is clearly superior to the stem."

Historical Context

The history and evolution of Lu Gen's use in Chinese medicine over the centuries

Lu Gen was first recorded in the Ming Yi Bie Lu (名医别录, Supplementary Records of Famous Physicians), compiled around the 5th century CE, where it was classified in the lower grade. The Xin Xiu Ben Cao (新修本草, Tang dynasty revised materia medica) described it as growing in low, damp ground with bamboo-like stems and flowers resembling silvergrass, noting it should be harvested in the 2nd and 8th lunar months and sun-dried.

A notable point of historical discussion surrounds the relationship between Lu Gen (the rhizome) and Wei Jing (苇茎, the aboveground stem). The famous Wei Jing Tang (苇茎汤) from Sun Simiao's Qian Jin Fang (千金方) originally called for the stem, not the root. Over time, pharmacies stopped stocking the stem, and Lu Gen became the standard substitute. The late Qing dynasty physician Zhang Xichun argued in his Yi Xue Zhong Zhong Can Xi Lu that the root is actually superior to the stem, reasoning that its cool nature and hollow structure make it especially effective at clearing Lung Heat and regulating Lung Qi, while its sweet, juicy quality better nourishes Lung Yin.

The name "Lu Gen" (芦根) literally means "reed root." Li Shizhen's Ben Cao Gang Mu referenced the Lei Gong Pao Zhi Lun preface, noting that Lu Gen combined with Hou Po (厚朴) was used to promote appetite and aid digestion, explaining that "Lu Gen's sweetness benefits the Stomach, and its coldness descends fire." During the COVID-19 pandemic in 2020, formulas containing Lu Gen (Wei Jing Tang and Wu Ye Lu Gen Tang) were included in China's national treatment protocols due to their Heat-clearing and Lung-supporting properties.

Modern Research

5 published studies investigating the pharmacological effects or clinical outcomes of Lu Gen

1

Systematic review and meta-analysis: Lu Gen for acute respiratory tract infections (2024)

Xie Y, Ruan G, Cheng J, Xiong H, Zhang J, Leung ELH, et al. Frontiers in Pharmacology, 2024, 15:1295753.

This systematic review examined 42 randomized controlled trials involving 6,879 patients with acute respiratory tract infections treated with formulas containing Phragmites communis (Lu Gen). The review searched eight databases and found that herbal formulations containing Lu Gen were commonly used in treating these infections. However, the overall quality of evidence was low, with 38 of 42 studies assessed as high risk of bias, highlighting the need for better-designed clinical trials.

PubMed
2

Narrative review: Traditional uses, phytochemistry, pharmacology and toxicology of Rhizoma phragmitis (2022)

Ren Y, Cui GD, He LS, Yao H, Zi CY, Gao YX. Chinese Journal of Integrative Medicine, 2022, 28(12): 1127-1136.

This comprehensive narrative review summarized the botany, phytochemistry, pharmacology, and toxicology of Lu Gen. It confirmed that modern pharmacological research demonstrates antiviral, antioxidative, anti-inflammatory, analgesic, and hypoglycemic properties, along with blood lipid-lowering and liver/kidney-protective effects. The review also noted Lu Gen's inclusion in China's COVID-19 treatment protocols.

3

Genotoxicity evaluation of Phragmitis rhizoma extract: in vitro and in vivo assays (2019)

Kim NS, Shin S, Shin GG, Bang OS. Journal of Ethnopharmacology, 2019, 241: 112025.

This safety study evaluated the genotoxic potential of an aqueous extract of Phragmitis rhizoma using OECD-compliant test methods. No genotoxic effects were found in the Ames bacterial reverse mutation test (up to 5000 micrograms/plate), the chromosomal aberration test (up to 500 micrograms/mL), or the in vivo bone marrow micronucleus test in mice (up to 5000 mg/kg/day for 2 days). The study concluded that the aqueous extract is safe regarding genotoxicity.

4

Polysaccharide-rich extract of Phragmites rhizoma attenuates stress and fatigue in rodents (2019)

Chung YH, Park TK, Yim SH, et al. Journal of Medicinal Food, 2019, 22(4): 355-364.

This preclinical study investigated the effects of a polysaccharide-rich extract from Phragmites rhizoma on stress-induced gastric ulcers and swimming-induced fatigue in rodents. Pretreatment with the extract effectively reversed stress-induced changes including elevated ulcer scores, cortisol levels, oxidative damage markers, and depleted antioxidant enzymes. It also significantly prolonged swimming endurance in mice.

5

Inhibitory effects of Phragmites rhizoma polysaccharides on atopic dermatitis in mice (2013)

Nam Y, Chung YH, Chu LY, et al. Life Sciences, 2013, 92: 866-872.

This preclinical study tested a polysaccharide-rich extract from Phragmites rhizoma on atopic dermatitis-like skin lesions in NC/Nga mice. The extract showed inhibitory effects on dermatitis symptoms, suggesting potential anti-inflammatory and immune-modulating properties relevant to allergic skin conditions.

PubMed

Research on individual TCM herbs is growing but still limited by Western clinical trial standards. These studies provide emerging evidence and should be considered alongside practitioner expertise.