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Medically reviewed on Jun 11, 2018

Scientific Name(s): Equisetum arvense L. Family: Equisetaceae

Common Name(s): Horsetail , bottle brush , scouring rush , shave grass , Dutch rush , pewterwort 1 , 2 , 3


Horsetail has been used as a diuretic, in the treatment of kidney and bladder ailments, as an astringent to stop bleeding and stimulate healing, as an antitubercular drug, and as a cosmetic component, although there is a lack of clinical trials.


A water extract of horsetail was used in a clinical study as a hypoglycemic in type 2 diabetes at 0.33 g/kg via the oral route. 4


No longer considered safe for use.


Information regarding safety and efficacy in pregnancy and lactation is lacking. Avoid use.


None well documented.

Adverse Reactions

No data.


Horsetail is of undefined safety and may be toxic, especially to children. Avoid use during pregnancy. 5


This plant is native to Europe, North America, North Africa, and northern Asia. 6 Horsetail is a pteridophyte more closely related to ferns than to flowering plants and produces spore-sacs that are visible during March through September. 1 This small, deep-rooted, rush-like perennial grows to about 0.3 m. It has hollow, pointed stems, scale-like leaves, and no flowers. Horsetail grows best in moist and shady areas. 3


Traditionally, the plant has been used as a diuretic, an antitubercular drug, and in the treatment of genitourinary and respiratory disorders, arthritis, and bleeding ulcers. 2 Owing to the abrasive nature of its high silica content, horsetail has been used to clean dishes, sand wood, and polish metal. 3 Externally, it has been used in cosmetics 7 and as an astringent to stop bleeding 8 and stimulate wound healing. 9


The stems of horsetail contain 5% to 8% of silica and silicic acids. The plant contains about 5% of a saponin called equisetonin, in addition to the flavone glycosides isoquercitrin, equisetrin, and galuteolin. 10 The sterol fraction of E. arvense contains beta-sitosterol, campestrol, isofucosterol, and trace amounts of cholesterol. 11 The alkaloid nicotine is present in minute amounts (less than 1 ppm) 10 but may account for a portion of the pharmacologic activity of the plant. The plant contains more than 15 types of bioflavonoids, as well as manganese, potassium, sulfur, and magnesium. 2 , 12 The cytokinin isopentenyladenosine has been identified in fertile fronds. 13

Uses and Pharmacology

Diuretic effects

The plant exerts slight diuretic activity, which may be due to the combined effects of equisetonin and the flavone glycosides.

Animal/Clinical data

Research reveals no animal or clinical data regarding the use of horsetail for diuretic effects.

Other uses

The historical data reporting the use of horsetail in the treatment of urological disorders, tuberculosis, or to enhance wound healing have been neither confirmed nor disproved.


A water extract of horsetail was used in a clinical study as a hypoglycemic in type 2 diabetes at 0.33 g/kg via the oral route. 4


Information regarding safety and efficacy in pregnancy and lactation is lacking. Avoid use.


None well documented.

Adverse Reactions

Research reveals little or no information regarding adverse reactions with the use of this product.


Horsetail has been listed as an herb of undefined safety by the FDA. 14 Ingestion of large amounts of the fern may be toxic. There have been reports of children being poisoned by using the stems as blowguns or whistles.

Crude horsetail contains the enzyme thiaminase, which destroys the B-vitamin thiamine. Thiaminase poisoning may lead to permanent liver damage. 1 The Canadian Health Protection Branch prohibits this enzyme in dietary supplements, and supplement manufacturers must provide supportive documentation of its removal. 2

In animals, the ingestion of horsetail produces muscle weakness, ataxia, weight loss, abnormal pulse rate, cold extremities, and fever. 15 These symptoms are similar to those seen in nicotine intoxication. Hay composed of 20% or more E. arvense produced these symptoms in 2 to 5 weeks. 9

E. palustre contains toxic alkaloids, 2 , 12 and cattle appear to recognize the odor of this species of horsetail and refuse to eat hay contaminated with about 12% E. palustre . 16 Horsetail also may induce seborrheic dermatitis in animals. 17 , 18


1. Hallowell M. Herbal Healing: A Practical Introduction to Medicinal Herbs . Garden City Park, NY: Avery Publishing Group; 1994.
2. Lininger S, Wright J, Austin S, Brown D, Gaby A. The Natural Pharmacy . Rocklin, CA: Prima Publishing; 1998.
3. Weiss G, Weiss S. Growing and Using the Healing Herbs . Avenel, NJ: Random House Publishing Inc.; 1992.
4. Revilla MC, Andrade-Cetto A, Islas S, Wiedenfeld H. Hypoglycemic effect of Equisetum myriochaetum aerial parts on type 2 diabetic patients. J Ethnopharmacol . 2002;81:117-120.
5. Somerville R. The Drug and Natural Medicine Advisor . Alexandria, VA: Time Life Inc.; 1997.
6. Chevallier A. The Encyclopedia of Medicinal Plants . New York, NY: DK Publishing Inc.; 1996.
7. Boruch T, Gora J, Kurowska A, Kalemba D, Swiatek L, Luczak S. Extracts of plants and their cosmetic application, Part V. Extracts from Equisetum arvense . Chem Abstracts . 1984;100.
8. Schauenberg P, Paris F. Guide to Medicinal Plants . New Canaan, CT: Keats Publishing; 1977.
9. Duke JA. Handbook of Medicinal Herbs . Boca Raton, FL: CRC Press; 1985.
10. Tyler VE. The New Honest Herbal . Philadelphia, PA: G.F. Stickley Co.; 1987.
11. D'Agostino M, Dini A, Pizza C, Senatore F, Aquino R. Sterols from Equisetum arvense . Boll Soc Ital Biol Sper . 1984;60:2241-2245.
12. Bisset N. Herbal Drugs and Phytopharmaceuticals . Boca Raton, FL: CRC Press; 2001.
13. Yamane H, Watanabe M, Satoh Y, Takahashi N, Iwatsuki K. Identification of cytokinins in two species of pteridophyte sporophytes. Plant Cell Physiol . 1983;24:1027.
14. Der Marderosian AH, Liberti LE. Natural Product Medicine . Philadelphia, PA: G.F. Stickley Co.; 1988.
15. Spoerke DG. Herbal Medications . Santa Barbara, CA: Woodbridge Press; 1980.
16. Kamphues J. Refusal of breeding bulls to eat hay contaminated with horsetail ( Equisetum palustre ) [in German]. Tierarztl Prax . 1990;18:349-351.
17. Sudan BJ. Seborrhoeic dermatitis induced by nicotine of horsetails ( Equisetum arvense L.). Contact Dermatitis . 1985;13:201-202.
18. Maeda H, Miyamoto K, Sano T. Occurrence of dermatitis in rats fed a cholesterol diet containing field horsetail ( Equisetum arvense L.). J Nutr Sci Vitaminol (Tokyo) . 1997;43:553-563.

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