Horsetail (Equisetum arvense)
Common names: Shave grass, scouring rush
Parts used and where grown: Horsetail is widely distributed throughout the temperate climate zones of the northern hemisphere, including Asia, North America and Europe.1 Horsetail is a unique plant with two distinctive types of stems. One variety of stem grows early in spring and looks like asparagus, except for its brown color and the spore-containing cones on top. The mature form of the herb, appearing in summer, has branched, thin, green, sterile stems and looks very much like a feathery tail.
In what conditions might horsetail be supportive?
Â¥ brittle nails
Â¥ edema (water retention)
Â¥ osteoarthritis Â¥ osteoporosis
Â¥ rheumatoid arthritis
Historical or traditional use: Since recommended by the Roman physician Galen, several cultures have employed horsetail as a folk remedy for kidney and bladder troubles, arthritis, bleeding ulcers, and tuberculosis. Additionally, the topical use of horsetail is said to stop the bleeding of wounds and promote rapid healing. The use of this herb as an abrasive cleanser to scour pots or shave wood illustrates the origin of horsetailÃ•s common namesÃ‘scouring rush and shave grass.2
Active constituents: Horsetail is very rich in silicic acid and silicates, which provide approximately 2-3% elemental silicon. Potassium, aluminum, and manganese along with fifteen different types of bioflavonoids are also found in the herb. The presence of these bioflavonoids are believed to cause the diuretic action, while the silicon content is said to exert a connective tissue strengthening and anti-arthritic action.3 Some experts have suggested that the element silicon is a vital component for bone and cartilage formation.4 This would indicate that horsetail may be beneficial in preventing osteoporosis. Anecdotal reports suggest that horsetail may be of some use in the treatment of brittle nails.
How much should I take? Horsetail can be taken daily as a tea at 1-4 grams per day. A tincture can also be used at 2-6 ml per day.
Are there any side effects or interactions? Horsetail is generally considered safe for non-pregnant adults at the recommended dose. The only concern would be that the correct species of horsetail is used; Equisetum palustre is another species of horsetail, which contains toxic alkaloids and is a well-known livestock poison.
The Canadian Health Protection Branch requires supplement manufacturers to document that their products do not contain the enzyme thiaminase, found in crude horsetail, which destroys the B vitamin thiamin. Since alcohol, temperature, and alkalinity neutralize this potentially harmful enzyme, tinctures, fluid extracts, or preparations of the herb subjected to 100Â°C temperatures during manufacturing should be the preferable form of the plant utilized for medicinal use.5
1. Leung AY, Foster S. Encyclopedia of Common Natural Ingredients Used in Foods, Drugs, and Cosmetics, 2nd ed. New York: John Wiley & Sons, 1996, 306&endash;8. 2. Castleman M. The Healing Herbs. Emmaus, PA: Rodale Press, 1991, 219&endash;21. 3. Weiss RF. Herbal Medicine. Gothenburg Sweden: Ab Arcanum, 1988, 238&endash;9. 4. Seaborn CD, Nielsen FH. Silicon: a nutritional beneficence for bones, brains and blood vessels? Nutr Today 1993;28:13&endash;18. 5. Fabre B, Geay B, Beaufils P. Thiaminase activity in Equisetum arvense and its extracts. Plant Med Phytother 1993;26:190&endash;97.
*These statements have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure or prevent any disease.