Herb Whole plant / Aerial parts (全草 quán cǎo)

Mu Zei

Horsetail herb · 木贼

Equisetum hiemale L. · Herba Equiseti Hiemalis

Also known as: Scouring Rush

Mu Zei (Horsetail herb) plant

Images shown are for educational purposes only

Mu Zei (scouring rush) is best known as an eye herb in Chinese medicine. It gently clears heat and wind from the eyes, making it especially useful for red, teary, or cloudy eyes. It also has a mild ability to help stop bleeding, though it is usually combined with other herbs for this purpose.

Category Cool, acrid herbs that release the Exterior (辛凉解表药)
Therapeutic focus Eye Health and Vision Skin Conditions

TCM Properties

Temperature

Neutral

Taste

Sweet (甘 gān), Bitter (苦 kǔ)

Channels entered

Lungs, Liver, Gallbladder

Parts used

Whole plant / Aerial parts (全草 quán cǎo)

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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 Mu Zei does in the body, explained in both everyday and TCM terms

Therapeutic focus

In practical terms, Mu Zei is primarily used to support these areas of health:

Eye Health and Vision Skin Conditions

TCM Actions

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

Disperses Wind-Heat Brightens the Eyes and Removes Visual Obstructions Stops Bleeding

How these actions work

'Disperses Wind-Heat' means Mu Zei gently pushes out Wind-Heat pathogens that have invaded the upper body, particularly the eyes and head. Because the Liver opens to the eyes, and Mu Zei enters the Liver and Gallbladder channels, it is especially suited for Wind-Heat that lodges in the Liver channel and attacks the eyes, causing redness, swelling, and tearing. Classical texts compare its dispersing action to that of Ma Huang (Ephedra), since both herbs share a similar hollow, jointed physical form, but Mu Zei is milder and neutral rather than warm and pungent.

'Brightens the eyes and removes superficial visual obstructions' (退翳 tuì yì) refers to Mu Zei's signature ability to help resolve corneal opacities, cloudy films, or nebulae (pterygium) that develop over the eye. In TCM, these visual obstructions often arise when Wind-Heat or Liver-Gallbladder fire causes stagnation in the blood vessels supplying the eyes. By dispersing wind and clearing heat from the Liver channel, Mu Zei helps restore clear vision. This is the herb's most celebrated and distinctive action.

'Stops bleeding' refers to Mu Zei's mild hemostatic effect. It can help with intestinal wind bleeding (blood in the stool from hemorrhoids), bloody dysentery, and uterine bleeding. However, this action is relatively weak, so Mu Zei is rarely used alone for bleeding and is typically combined with stronger hemostatic herbs like Huai Hua (Sophora flower) or Jing Jie Tan (charred Schizonepeta).

Patterns Addressed

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

Why Mu Zei addresses this pattern

Mu Zei is sweet, bitter, and neutral, entering the Lung, Liver, and Gallbladder channels. Its light, hollow structure gives it an upward and outward dispersing tendency that is ideal for expelling Wind-Heat pathogens from the head and eyes. In Wind-Heat patterns, the pathogen attacks the upper body and especially the eyes (since the Liver opens to the eyes). Mu Zei's ability to enter the Liver and Gallbladder blood level allows it to drive out Wind-Heat directly from these channels, restoring clear flow of blood to the eyes and resolving redness, swelling, and tearing.

A practitioner would look for one or more of these signs

Red Eyes

Red, swollen, painful eyes from Wind-Heat invasion

Excessive Sweating

Tearing that worsens with wind exposure

Blurry Vision

Cloudy or blurred vision with corneal opacity

Commonly Used For

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

Arises from: Wind-Heat Liver Fire Blazing

TCM Interpretation

In TCM, acute red eyes are most often understood as Wind-Heat invading the upper body and lodging in the eye region, or as Liver Fire flaring upward (since the Liver opens to the eyes). The Liver and Gallbladder channels both connect to the eye area, so heat in these channels readily manifests as eye redness, swelling, pain, and excessive tearing. Chronic or recurrent cases may involve underlying Liver Yin Deficiency generating internal heat that rises to the eyes.

Why Mu Zei Helps

Mu Zei directly enters the Liver and Gallbladder channels and specializes in dispersing Wind-Heat from the eye region. Its bitter taste helps drain excess heat, while its light, hollow structure carries its effects upward to the head and eyes. Classical sources call it a 'key remedy for removing visual obstructions and brightening the eyes.' For acute conjunctivitis, it is commonly paired with Ju Hua (chrysanthemum), Jue Ming Zi (cassia seed), and Chan Tui (cicada shell) to strengthen its Wind-Heat clearing action at the eyes.

Also commonly used for

Blurry Vision

Corneal opacities, pterygium, nebulae

Excessive Sweating

Tearing that worsens with wind exposure

Hemorrhoids

Bleeding hemorrhoids (as adjunct herb)

Dark Blood In Stool

Intestinal wind bleeding

Rectal Prolapse

Used externally as charred powder for rectal prolapse

Dysentery

Bloody dysentery

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

Sweet (甘 gān), Bitter (苦 kǔ)

Channels Entered

Lungs Liver Gallbladder

Parts Used

Whole plant / Aerial parts (全草 quán cǎo)

Dosage & Preparation

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

Standard dosage

3–9g

Maximum dosage

Up to 15g in specific clinical situations (e.g. acute eye conditions or bleeding), under practitioner supervision only. Standard use should not exceed 9g.

Dosage notes

For eye conditions (Wind-Heat eye redness, corneal opacities, excessive tearing): the standard range of 3 to 9g is typically sufficient. For hemostatic purposes (intestinal wind bleeding, hemorrhoidal bleeding): some classical formulas use up to 15g, often after dry-frying (chao tan) to enhance the astringent and hemostatic effect. When used to promote sweating for exterior Wind-Cold patterns (a less common application), decoct with fresh ginger and scallion. Avoid higher doses in patients with Qi or Blood deficiency, as the dispersing action may worsen depletion.

Preparation

No special decoction handling required. Standard decoction is the usual method. For hemostatic purposes, the herb is sometimes dry-fried until charred (chao tan cun xing, 炒炭存性) before decocting. Historically, some formulas specified removing the nodes (qu jie, 去节) before use, though modern practice generally uses the herb with nodes intact.

Processing Methods

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

Processing method

The herb is stir-fried (dry-fried) until slightly darkened. The nodes (joints) are traditionally removed before processing.

How it changes properties

Stir-frying moderates the herb's dispersing nature and enhances its hemostatic (止血) action. The thermal nature remains neutral but the astringent quality becomes slightly more pronounced, making it more suitable for bleeding conditions.

When to use this form

Used when the primary goal is to stop bleeding, such as in intestinal wind bleeding, bloody dysentery, or uterine bleeding. The raw form is preferred for dispersing Wind-Heat and clearing eye conditions.

Common Herb Pairs

These ingredients are traditionally combined with Mu Zei for enhanced therapeutic effect

Cang Zhu
Cang Zhu 1:1 (Mu Zei 30g : Cang Zhu 30g, ground to powder, taken 6g per dose as in the Sheng Hui Fang)

Mu Zei disperses Wind-Heat from the Liver channel and clears visual obstructions, while Cang Zhu (Atractylodes) dries Dampness and has a traditional reputation for treating night blindness and visual dimness. Together they enhance the wind-dispersing and vision-brightening effect, addressing both the Wind-Heat component and any underlying Dampness clouding the eyes.

When to use: For blurred vision with excessive tearing, night blindness, or visual dimness, especially when accompanied by a sensation of heaviness or Dampness.

Chan Tui
Chan Tui 1:1

Both herbs disperse Wind-Heat and brighten the eyes, but Mu Zei is stronger at removing corneal opacities (退翳), while Chan Tui (cicada shell) excels at dispersing Wind-Heat more broadly and also calms itching and spasms. Together they provide a comprehensive approach to Wind-Heat eye disorders.

When to use: For Wind-Heat attacking the eyes with redness, swelling, tearing, and corneal cloudiness or pterygium.

Xiang Fu
Xiang Fu 1:1 (Xiang Fu 30g : Mu Zei 30g, decocted and used as topical wash)

Mu Zei disperses Wind-Heat from the surface, while Xiang Fu (Cyperus) moves Qi and Blood stagnation. Together they address both the external pathogen (Wind-Heat toxin) and the local stagnation that underlies warts and skin growths.

When to use: For flat warts (verruca plana). Typically used as an external decoction wash applied to the affected skin.

Gu Jing Cao
Gu Jing Cao 1:1

Both herbs specialize in clearing Wind-Heat from the eyes and removing visual obstructions. Gu Jing Cao (Eriocaulon) is particularly good for treating star-shaped corneal opacities, while Mu Zei is stronger for film-like nebulae. Together they cover a broader range of corneal pathology.

When to use: For persistent corneal opacities, pterygium, or chronic eye cloudiness from Wind-Heat or Liver-channel heat.

Comparable Ingredients

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

Chan Tui
Mu Zei vs Chan Tui

Both Mu Zei and Chan Tui disperse Wind-Heat and brighten the eyes, and they are commonly used together for eye disorders. However, Mu Zei is stronger at physically resolving corneal opacities and films (退翳), while Chan Tui has broader applications including relieving itching, promoting rash eruption, calming spasms (息风止痉), and soothing the throat. Chan Tui is the better choice when Wind-Heat eye problems are accompanied by skin itching or convulsions. Mu Zei is preferred when the primary concern is a stubborn corneal opacity.

Gu Jing Cao
Mu Zei vs Gu Jing Cao

Both are premier eye herbs that clear Wind-Heat and remove visual obstructions. Gu Jing Cao (Eriocaulon) enters the Liver and Stomach channels and is considered slightly better for star-shaped corneal opacities and headache with eye pain. Mu Zei enters the Lung, Liver, and Gallbladder channels and is considered stronger for film-like corneal nebulae. A classical teaching notes that Gu Jing Cao removes star opacities while Mu Zei removes film opacities, so the choice depends on the type of visual obstruction.

Ju Hua
Mu Zei vs Ju Hua

Both clear heat from the Liver and brighten the eyes. Ju Hua (chrysanthemum) is cool and has a broader profile: it also calms Liver Yang, nourishes Liver Yin (especially when combined with tonifying herbs), and treats headache and dizziness. However, Ju Hua cannot remove established corneal opacities the way Mu Zei can. For red eyes without corneal cloudiness, Ju Hua is sufficient and gentler. When there is an actual corneal opacity or pterygium, Mu Zei is essential.

Identity & Adulterants

Related species and common adulterations to be aware of when sourcing Mu Zei

The most common substitution issue involves Jie Jie Cao (节节草, Equisetum ramosissimum Desf.), a related species sometimes sold as or mixed with Mu Zei. This confusion dates back to the Qing Dynasty. Jie Jie Cao has branching stems (while true Mu Zei is usually unbranched), is generally thinner and softer, and has somewhat different therapeutic properties (more oriented toward clearing Heat, promoting urination, and resolving phlegm). In southern regions such as Yunnan, Guangdong, and Guangxi, a species called 'Tu Mu Zei' (土木贼, slender scouring rush) may also be substituted. Authentic Mu Zei (E. hyemale) can be distinguished by its unbranched, sturdy stems with 18-30 prominent silica-rich ridges that feel distinctly rough, and its characteristic black-brown banding at each node.

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

Toxicity Classification

Classical Chinese pharmacopoeia toxicity rating for Mu Zei

Non-toxic

Classified as non-toxic in the Chinese Pharmacopoeia and described as such since the Jia You Ben Cao. However, the whole plant does contain thiaminase (an enzyme that destroys vitamin B1), silicates, and small amounts of alkaloids. In animals (particularly livestock), prolonged ingestion of Equisetum species can cause thiamine deficiency leading to symptoms such as muscle weakness, tremor, incoordination, and cold extremities, which can be reversed with high-dose vitamin B1. In mice, the LD50 of the water extract by intraperitoneal injection is approximately 49 g/kg, indicating very low acute toxicity. At standard human medicinal doses (3 to 9 g in decoction), Mu Zei is considered safe for short-term use. Prolonged or excessive use should be avoided.

Contraindications

Situations where Mu Zei should not be used or requires extra caution

Caution

Qi and Blood deficiency. Mu Zei has a dispersing and scraping nature that can further deplete Qi and Blood in those already deficient. The classical caution states: 'Qi and Blood deficient persons should use with caution.'

Caution

Yin deficiency with dryness. The herb's ascending and dispersing properties can further consume Yin fluids, worsening dryness symptoms.

Caution

Bleeding disorders due to Qi deficiency failing to hold Blood. Though Mu Zei can stop bleeding from Wind-Heat or Blood-Heat causes, it is inappropriate when bleeding results from weakness and inability of Qi to contain Blood.

Caution

Excessive or prolonged use. Long-term consumption may potentially cause liver stress. Should be used for limited courses under professional guidance.

Special Populations

Important considerations for pregnancy, breastfeeding, and pediatric use

Pregnancy

Use with caution during pregnancy. While classical sources include a formula using Mu Zei with Chuan Xiong and Jin Yin Hua for 'restless fetus' (Sheng Ji Zong Lu), this represents a specific therapeutic application under expert guidance, not a general safety endorsement. Mu Zei's dispersing and Blood-moving properties could theoretically disturb the fetus. Pregnant women should only use this herb under direct supervision of a qualified practitioner.

Breastfeeding

No specific classical or modern safety data is available for breastfeeding. Given its mild dispersing nature and the potential presence of thiaminase and alkaloids, cautious short-term use at low standard doses is generally considered acceptable, but prolonged use should be avoided. Consult a qualified practitioner before use while breastfeeding.

Children

Mu Zei may be used in children at reduced dosages proportional to age and body weight (generally one-third to one-half the adult dose for children over 3 years). Due to the herb's dispersing nature, it should be used cautiously and for short durations in children, as their Qi and Blood are naturally less robust. Not recommended for infants or very young children without specific practitioner guidance.

Drug Interactions

If you are taking pharmaceutical medications, be aware of these potential interactions with Mu Zei

No well-documented drug interactions specific to Mu Zei (Equisetum hyemale) exist in the peer-reviewed clinical literature. However, based on known pharmacological properties, the following theoretical considerations apply:

  • Anticoagulant and antiplatelet medications (warfarin, aspirin, clopidogrel): Mu Zei extracts have demonstrated anticoagulant and antiplatelet aggregation effects in laboratory studies (via ferulic acid content). Concurrent use may theoretically potentiate bleeding risk.
  • Antihypertensive medications: Mu Zei alcohol extracts show sustained blood pressure-lowering effects in animal models. Combined use with antihypertensive drugs may lead to additive hypotensive effects.
  • Thiamine (vitamin B1) and thiamine-dependent medications: Equisetum species contain thiaminase, which can degrade thiamine. Prolonged use could theoretically worsen thiamine deficiency in susceptible individuals.
  • Lithium and diuretics: Equisetum species have shown diuretic activity. Combined use with lithium or other diuretics may alter electrolyte balance or drug levels.

Dietary Advice

Foods and dietary considerations when taking Mu Zei

No specific strong dietary restrictions apply. As Mu Zei is used primarily for Wind-Heat and Liver-related eye conditions, it is generally advisable to avoid excessively spicy, greasy, and fried foods during treatment, as these can generate further Heat and aggravate eye inflammation. Alcohol should also be moderated, as it generates Heat and rises to the head and eyes.

Botanical Description

Physical characteristics and morphology of the Mu Zei source plant

Equisetum hyemale L. (rough horsetail or scouring rush) is an evergreen perennial pteridophyte (fern ally) belonging to the Equisetaceae family. It is one of the most ancient living plant lineages, with relatives dating back over 350 million years to the Devonian period. The plant spreads via aggressive underground rhizomes that are black-brown in color with yellowish-brown hairs at the nodes.

The aerial stems are erect, unbranched, hollow, and jointed, typically growing 30 to 100 cm tall (sometimes exceeding one meter) with a diameter of 3 to 8 mm. The dark green stems have 18 to 30 conspicuous longitudinal ridges impregnated with silica, making them notably rough to the touch. At each node, there are tubular sheath-like scale leaves with black-brown bases and tips. The plant reproduces by spores rather than seeds, producing small oval spore-bearing cones (strobili) at the stem tips.

E. hyemale grows in moist to wet habitats including shaded mountain slopes, forest understories, riverbanks, stream margins, and damp grasslands. It thrives in heavy clay or sandy soils and can tolerate occasional flooding, growing from sea level up to about 2,500 meters elevation.

Sourcing & Harvesting

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

Harvesting season

Summer and autumn. The aerial stems are cut, cleared of debris and dead material, then dried in the sun or shade.

Primary growing regions

Historically, the classical 'terroir' (dao di) region was Qinzhou (秦州), corresponding to the modern Tianshui area of Gansu province. In modern times, the highest-quality Mu Zei is widely considered to come from Liaoning province and the broader northeast China region (Dongbei). Major production areas include Heilongjiang, Jilin, Liaoning, Hebei, Inner Mongolia, Shaanxi, Gansu, Xinjiang, Qinghai, Shanxi, Anhui, Hubei, Sichuan, and Guizhou provinces. The plant also grows widely across temperate Eurasia, Japan, Korea, and Russia.

Quality indicators

Good quality Mu Zei consists of long, thick, intact stems that are greenish in color, with firm, thick walls. The surface ridges should be sharp and rough to the touch (due to silica content), and the nodes should not be separated or broken apart. The cross-section shows a hollow center surrounded by multiple small round cavities. The taste should be mildly sweet, slightly bitter, and faintly astringent, with a gritty or sandy sensation when chewed (from silica). Avoid material that is yellowish-brown, brittle, crumbling at the nodes, thin-walled, or extensively fragmented.

Classical Texts

Key passages from the classical Chinese medical texts that describe Mu Zei and its therapeutic uses

Jia You Ben Cao (嘉祐本草, Song Dynasty)

Chinese: 主目疾，退翳膜。又消积块，益肝胆，明目，疗肠风，止痢及妇人月水不断。

English: Treats eye diseases and disperses corneal opacities (pterygium). Also dissolves masses, benefits the Liver and Gallbladder, brightens the eyes, treats intestinal wind (bleeding), stops dysentery, and treats women's continuous menstrual bleeding.

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

Chinese: 木贼，与麻黄同形同性，故亦能发汗解肌，升散火郁风湿，治眼目诸血疾也。

English: Mu Zei is similar in form and nature to Ma Huang. Therefore it can also promote sweating and release the muscle layer, disperse pent-up Fire and Wind-Dampness, and treat all Blood disorders of the eyes.

Ben Cao Jing Shu (本草经疏, Ming Dynasty)

Chinese: 木贼草，首主目疾，及退翳膜，益肝胆而明目也。其主积块、疗肠风、止痢，及妇人月水不断、崩中赤白、痔疾出血者，皆入血益肝胆之功，肝藏血故也。

English: Mu Zei primarily treats eye diseases and removes corneal opacities by benefiting the Liver and Gallbladder to brighten the eyes. Its ability to treat masses, intestinal wind, dysentery, women's incessant menses, flooding with red or white discharge, and hemorrhoidal bleeding all stem from its action of entering the Blood level and benefiting the Liver and Gallbladder, because the Liver stores Blood.

Ben Cao Qiu Zhen (本草求真, Qing Dynasty)

Chinese: 木贼，形质有类麻黄，升散亦颇相似，但此气不辛热，且入足少阳胆、足厥阴肝，能于二经血分驱散风热，使血上通于目，故为去翳明目要剂。

English: Mu Zei resembles Ma Huang in form and quality, and its ascending and dispersing nature is also quite similar. However, its Qi is not acrid-hot, and it enters the Foot Shaoyang Gallbladder and Foot Jueyin Liver channels, where it can expel Wind-Heat from the Blood level of these two channels and direct Blood upward to the eyes. Therefore it is an essential remedy for removing opacities and brightening the eyes.

Historical Context

The history and evolution of Mu Zei's use in Chinese medicine over the centuries

Mu Zei first appeared in herbal literature during the Tang Dynasty in the Zhen Yuan Guang Li Fang (贞元广利方). Its first major monograph entry was in the Song Dynasty's Jia You Ben Cao (嘉祐本草, 1060 CE), which established its primary indications for eye diseases, corneal opacities, intestinal bleeding, and menstrual disorders. The name has been the mainstream designation ever since, though the herb has also been known by folk names such as Cuo Cao (锉草, 'filing grass'), Bi Tong Cao (笔筒草, 'brush-tube grass'), and Jie Jie Cao (节节草, 'joint-by-joint grass').

The name 'Mu Zei' (木贼, literally 'wood thief') was explained by Li Shizhen in the Ben Cao Gang Mu: the plant's rough, silica-laden stems were used by woodworkers to polish and smooth wood surfaces, 'filing' the wood like a thief that eats away at it. The character 'zei' (贼) alludes to the Er Ya (尔雅), an ancient dictionary, where insects that gnaw at plant joints are called 'zei.' Li Shizhen also drew attention to Mu Zei's strong physical resemblance to Ma Huang (Ephedra), noting they share a similar form with hollow, jointed, ridged stems, but differ in therapeutic nature: Mu Zei is mild and enters the Liver and Gallbladder Blood level, while Ma Huang is acrid-hot and opens the exterior.

During the Qing Dynasty, there was some confusion with the closely related species Jie Jie Cao (Equisetum ramosissimum), which was occasionally substituted for Mu Zei. Classical texts consistently emphasize that Mu Zei is most valued as an ophthalmology herb, earning it the reputation as an essential medicine for removing corneal opacities (yi zhang, 翳障). The Ben Cao Zheng Yi (本草正义) provided an important clinical caveat: though Mu Zei treats various bleeding conditions, its strong scraping and dispersing power means it should only be used in conditions of excess, and clinicians must be cautious in patients with Qi deficiency.

Modern Research

4 published studies investigating the pharmacological effects or clinical outcomes of Mu Zei

1

Phytochemical Characterization, Antimicrobial Activity, and Antioxidant Potential of Equisetum hyemale L. (Equisetaceae) Extracts (in vitro study, 2015)

Do Prado RF, Boligon AA, de Freitas RB, et al. Journal of Medicinal Food, 2015, 18(7): 830-834.

This study was the first to characterize the phytochemistry of E. hyemale extracts (70% ethanol and methanol) and evaluate their biological activity. The extracts contained significant phenolic compounds and demonstrated free-radical scavenging (antioxidant) activity as well as antimicrobial effects against both bacteria and fungi in laboratory testing.

PubMed
2

Antimicrobial, Antitrypanosomal and Antibiofilm Activity of Equisetum hyemale (in vitro study, 2016)

Dos Santos Alves CF, Bonez PC, de Souza ME, et al. Microbial Pathogenesis, 2016, 101: 119-125.

This study evaluated E. hyemale extracts against a panel of pathogenic microorganisms and parasites. The extracts showed antimicrobial activity against Staphylococcus aureus and other clinically relevant bacteria, and also demonstrated antitrypanosomal and antibiofilm properties, supporting the traditional use of this plant for infectious and inflammatory conditions.

3

Horsetail (Equisetum hyemale) Extract Accelerates Wound Healing in Diabetic Rats by Modulating IL-10 and MCP-1 Release and Collagen Synthesis (preclinical study, 2023)

Aguayo-Morales H, Sierra-Rivera CA, Claudio-Rizo JA, Cobos-Puc LE. Pharmaceuticals (Basel), 2023, 16(4): 514.

This study investigated E. hyemale extract in diabetic rat wound models. The extract accelerated wound healing by modulating inflammatory cytokines (reducing pro-inflammatory markers while promoting anti-inflammatory IL-10) and stimulating collagen synthesis. The extract also demonstrated antimicrobial activity against S. aureus, a common wound-infecting strain.

4

Diuretic Activity of Mexican Equisetum (preclinical study, 1985)

Pérez Gutiérrez RM, Laguna GY, Walkowski A. Journal of Ethnopharmacology, 1985, 14(2-3): 269-272.

Chloroform extracts of several Equisetum species, including E. hiemale var. affine, were tested for diuretic activity in mice. E. hiemale var. affine was the most active species tested, producing diuretic effects comparable to hydrochlorothiazide in terms of sodium, potassium, and chloride excretion.

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.