Botanical name

Equisateaceae - Equisetum arvense L.

Family

Horsetail family (Equisetaceae)

Common name

Horsetail

Information about the plant

Horsetails are spore plants, which were numerous in the Mesozoic period but only have about 30 species in the world. However, these are spread around the earth, so that the common horsetail grows in the temperate zones of the northern hemisphere. The upright hollow stem whorl branches at short intervals. At the junction a ring is formed of scaly, pointed, small flakes intergrown with each other, like a virtual leaf sheath. The individual internodes "nest" in this. The genus name of Equisetum comes from the Latin "equus" (= horse) and from Latin "seta" (= animal hair, bristles), which refer to the stiff bristle hairs of the mane on a horse, which is like the horsetail. Because of the silica deposits, the stems are rough and hard, so the plant was used previously as an abrasive, in particular as a cleaning agent for pewter. Horsetail is a spore plant. In the spring it pushes out unbranched fertile shoots with terminal cone-like, brownish sporophylls. When they die, the following summer they grow to 50cm tall green, lively green-branched sterile shoots.

Medicinally used parts of plants (herbal drug)

The sterile, aerial parts of green plant are used. The commercially available drug comes from eastern and southern Europe or China.

Constituents of the herbal drug

Horsetail contains silica and silicates, flavonoids, caffeic acid derivatives.

Quality of the drug

The quality of the horsetail (Equiseti herba) is specified in the European Pharmacopoeia (Ph. Eur.).

Medical applications

Recognised medical use

Internally for post-traumatic and static oedema and flushing in bacterial and inflammatory diseases of the urinary tract and renal gravel. Externally to support the treatment of slowly healing wounds (Commission E). The HMPC has classified horsetails as a traditional herbal medicinal product (§ 39a AMG) (see "traditional use").

Traditional use

The HMPC has classified horsetail as a traditional herbal medicine. Based on many years of experience horsetail can be used for mild urinary problems, i.e. to increase the amount of urine for the purpose of flushing the urinary tract. Traditionally used in combination with other drugs to support the excretory function of the kidney (traditional use acc. to § 109a).

Herbal drug preparations in finished dosage forms

• cut drug to prepare tea
• powdered drug in tablets
• dried extracts in tablets and capsules
• alcoholic extracts and drops in juice
• mother tincture

Dosage

Prepared drugs: see package insert;
Tea infusion: drink a cup of warm horsetail tea several times a day. Average daily dose: 6g of the drug.

Preparation of a tea

Pour boiling water over 2-4 cups of finely chopped horsetail and boiled for 5 min. Then leave the mixture to stand for 10 to 15 minutes and strain trough a tea strainer.

Notes

It should be avoided if the person has an existing allergy to horsetail. For the flushing treatment, the person must drink an increased amount of fluid. If the person has an impaired heart or kidney function the fluid intake is restricted so the flushing therapy may not be carried out with horsetail. The intake of horsetail during pregnancy and breast-feeding is not recommended, because there are as yet no findings on its safety likewise for use in children under 12 years old.

Side effects

May result in mild stomach discomfort.

Interactions

None known

References

Herbal drug monographs

HMPC, Commission E

Further literature

Wichtl: Teedrogen und Phytopharmaka, pg. 244
Schilcher: Leitfaden Phytotherapie, pg. 231
Van Wyk: Handbuch der Arzneipflanzen, pg. 136
Kommentar zum Europäischen Arzneibuch (Horsetail, no. 1825)