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Horsetail

Field horsetail, colloquially known as horsetail, is a plant whose aerial parts are used to make medicine. Horsetail is used for water retention, oedema, kidney and bladder stones, urinary tract infections, incontinence and general disorders of the kidneys and bladder. In addition, horsetail is used for hair loss, tuberculosis, jaundice, hepatitis, brittle fingernails, joint diseases, gout, osteoarthritis, osteoporosis, frostbite, menstrual problems and uncontrolled bleeding in the nose, lungs and stomach. Horsetail is also applied to the skin for wounds and burns.

There are reports of horsetail products being contaminated with a related plant called Equisetum Palustre. This plant contains chemicals that can be toxic to cattle but have not been proven to be toxic to humans.

How effective is horsetail?

There is not enough scientific data to make a statement about the effectiveness of horsetail for kidney and bladder stones, hair loss, gout, chilblains, menstrual problems, water retention, urinary tract infections and incontinence, as well as for promoting wound healing. Further scientific research is required for this.

How does horsetail work?

The chemicals contained in horsetail may have antioxidant and anti-inflammatory effects. Plants related to horsetail contain chemicals that have a diuretic effect and increase urine excretion. However, it is not yet clear whether horsetail has the same effect.

Are there any safety concerns?

Horsetail is probably not safe and harmless when taken orally over a long period of time. It contains a chemical called thiaminase, which breaks down vitamin B1 (thiamine) and can potentially lead to thiamine deficiency. Some products are sold as thiaminase-free, but there is not enough scientific information regarding the safety of these products.

Precautions and warnings

Pregnancy and breastfeeding: Not enough is known about the safety of horsetail during pregnancy and breastfeeding, so pregnant and breastfeeding women should avoid horsetail to be on the safe side.

Diabetes: Horsetail can reduce blood sugar levels. Diabetics should therefore watch out for symptoms of low blood sugar and carefully monitor their blood sugar levels when using horsetail.

Low potassium levels: Horsetail may flush potassium from the body, possibly resulting in low potassium levels. Until more information is available on this, people who are at increased risk of potassium deficiency should be cautious when using horsetail.

Vitamin B1 (thiamine) deficiency: There are concerns that horsetail may exacerbate vitamin B1 deficiency.

Interactions with medications

Care should be taken when combining horsetail with lithium. Horsetail can have a dehydrating (diuretic) effect. Taking horsetail can interfere with the body's excretion of lithium, which could result in increased lithium levels and serious side effects. For this reason, it is important to consult your doctor before using horsetail if you are taking lithium. The lithium dosage may need to be adjusted.

Are there any interactions with medicinal herbs and supplements?

Areca

Both horsetail and betel nut (areca) reduce the amount of vitamin B1 available to the body. The combination of horsetail and areca can increase the risk of vitamin B1 deficiency.

Chromium-containing plant extracts and supplements

Horsetail contains chromium and may increase the risk of chromium toxicity when taken in conjunction with chromium supplements or medicinal herbs that contain chromium. Medicinal herbs that contain chromium include blueberries, brewer's yeast and buckthorn.

Vitamin B1 (thiamine)

Horsetail contains a chemical called thiaminase, which breaks down thiamine. Cattle that consumed a lot of horsetail were found to be deficient in vitamin B1.

Are there any interactions with food?

There are no known interactions with food.

Dosage

The correct dosage of horsetail depends on various factors such as age, state of health and others. At the present time, there is insufficient scientific data to be able to make a statement about appropriate dosage ranges for horsetail. For this reason, you should follow the dosage instructions on the label and/or consult a doctor or pharmacist before use.

References

  1. Agustin-Ubide MP, Martinez-Cocera C, Alonso-Llamazares A, et al. Diagnostic approach to anaphylaxis by carrot, related vegetables and horsetail (Equisetum arvense) in a homemaker. Allergy 2004;59:786-7.
  2. Revilla MC, Andrade-Cetto A, Islas S, Wiedenfeld H. Hypoglycemic effect of Equisetum myriochaetum aerial parts on type 2 diabetic patients. J Ethnopharmacol 2002;81:117-20.
  3. Lemus I, Garcia R, Erazo S, et al. Diuretic activity of an Equisetum bogotense tea (Platero herb): evaluation in healthy volunteers. J Ethnopharmacol 1996;54:55-8.
  4. Perez Gutierrez RM, Laguna GY, Walkowski A. Diuretic activity of Mexican equisetum. J Ethnopharmacol 1985;14:269-72.
  5. Fabre B, Geay B, Beaufils P. Thiaminase activity in equisetum arvense and its extracts. Plant Med Phytother 1993;26:190-7.
  6. Henderson JA, Evans EV, McIntosh RA. The antithiamine action of Equisetum. J Am Vet Med Assoc 1952;120:375-8.
  7. Ramos JJ, Ferrer LM, Garcia L, et al. Polioencephalomalacia in adult sheep grazing pastures with prostrate pigweed. Can Vet J 2005;46:59-61.
  8. Husson GP, Vilagines R, Delaveau P. [Antiviral properties of various extracts of natural origin]. Ann Pharm Fr 1986; 44:41-8.
  9. Do Monte FH, dos Santos JG Jr, Russi M, et al. Antinociceptive and anti-inflammatory properties of the hydroalcoholic extract of stems from Equisetum arvense L. in mice. Pharmacol Res 2004;49:239-43.
  10. Correia H, Gonzalez-Paramas A, Amaral MT, et al. Characterization of polyphenols by HPLC-PAD-ESI/MS and antioxidant activity in Equisetum telmateia. Phytochem Anal 2005;16:380-7.
  11. Langhammer L, Blaszkiewitz K, Kotzorek I. Evidence of toxic adulteration of equisetum. Dtsch Apoth Ztg 1972;112:1751-94.
  12. Dos Santos JG Jr, Blanco MM, Do Monte FH, et al. Sedative and anticonvulsant effects of hydroalcoholic extract of Equisetum arvense. Fitoterapia 2005;76:508-13.
  13. Sakurai N, Iizuka T, Nakayama S, et al. [Vasorelaxant activity of caffeic acid derivatives from Cichorium intybus and Equisetum arvense]. Yakugaku Zasshi 2003;123:593-8.
  14. Oh H, Kim DH, Cho JH, Kim YC. Hepatoprotective and free radical scavenging activities of phenolic petrosins and flavonoids isolated from Equisetum arvense. J Ethnopharmacol 2004;95:421-4.
  15. Sudan BJ. Seborrhoeic dermatitis induced by nicotine of horsetails (Equisetum arvense L.). Contact Dermatitis 1985;13:201-2.
  16. Piekos R, Paslawska S. Studies on the optimum conditions of extraction of silicon species from plants with water. I. Equisetum arvense L. Herb. Planta Med 1975;27:145-50.
  17. Health Canada. Labelling Standard: Mineral Supplements. Available at: http://www.hc-sc.gc.ca/dhp-mps/prodpharma/applic-demande/guide-ld/label-etiquet-pharm/minsup_e.html (Accessed November 14, 2005).
  18. Vimokesant S, Kunjara S, Rungruangsak K, et al. Beriberi caused by antithiamin factors in food and its prevention. Ann N Y Acad Sci 1982;378:123-36.
  19. Lanca S, Alves A, Vieira AI, et al. Chromium-induced toxic hepatitis. Eur J Intern Med 2002;13:518-20.