Plant Profile

Field Horsetail

Equisetum arvense
Family: Equisetaceae  ·  Parts used: Stem, Whole plant  ·  Also known as: common horsetail, horse pipes, mare's tail, scouring rush

The complete database record: 3 documented constituents, 6 pharmacological actions, 11 traditional / indicated uses, with 20 cited sources.

Botanical Description

Perennial, spore-bearing (non-flowering) plant with two distinct stem types arising from a deep, black, jointed rhizome. In early spring, unbranched, pale brownish fertile stems appear first, each topped with a spore-bearing cone, and die back once spores are shed; these are followed by the familiar green, hollow, jointed, ridged sterile stems bearing whorls of thin, needle-like branches at each node, giving a bottlebrush appearance.

Height: 20-80 cm (sterile stems)
Habit: Perennial, spore-bearing (non-flowering) herb with separate fertile and sterile stems
Leaves: Reduced to small, fused, toothed sheaths at each stem node (true leaves absent)
Flowers: None; reproduces by spores borne in a cone atop the unbranched fertile spring stems
Stem: Hollow, jointed, ridged green sterile stems with whorled branches; separate pale unbranched fertile stems in spring
Root: Deep, black, jointed, far-spreading rhizome
Fruit: Spores released from the fertile cone, not a true fruit
Flowering Period: Not applicable (spore-bearing); fertile stems appear in early spring

Habitat & Distribution

Grows in damp grassland, waste ground, riverbanks, roadsides and disturbed soil on a wide range of soils; native and common across the temperate Northern Hemisphere (Europe, Asia, North America).

Harvesting

The green sterile stems are cut in summer, at their most vigorous, and dried quickly in a warm, shaded, airy place; careful identification against the more toxic marsh horsetail (Equisetum palustre), which grows in similar damp ground, is essential before wild-harvesting.

Parts: Stem, Whole Plant
Season: Summer, when sterile stems are fully grown

Key Constituents

Silica (silicic acid)[12]

Field horsetail is exceptionally rich in silica, concentrated in the stem, and is a signature source of this mineral in Western herbal medicine.

Silica
Flavonoids[12]

Antioxidant flavonoids contributing to the plant's anti-inflammatory activity.

Flavonoids
Thiaminase[12]

An enzyme that degrades vitamin B1 (thiamine); the basis of the caution against prolonged or excessive use.

Pharmacological Actions

Anti-inflammatory[2, 3, 5, 12, 13, 14, 15]
Anti-rheumatic / anti-arthritic[2, 12, 13, 14, 15]
Anticancer (preclinical)[4]
Antimicrobial[12, 13, 14, 15]
Diuretic[12, 13, 14, 15]
Vulnerary (wound healing)[12, 13, 14, 15]

Traditional & Indicated Uses

Arthritis / joint pain[2, 15]Preliminary · 1/10

inferred from anti-inflammatory action

Mechanistic Exclude Ids: REF-0041, REF-0083, REF-0117, REF-1401
Evidence: 1
Label: Arthritis / joint pain

more plants for arthritis / joint pain →detailed sources →

Back pain[15]Preliminary · 1/10

inferred from anti-rheumatic action

Mechanistic Exclude Ids: REF-0041, REF-0083, REF-0117
Evidence: 1
Label: Back pain

more plants for back pain →detailed sources →

Bruising[15]Preliminary · 1/10

inferred from vulnerary action

Mechanistic Exclude Ids: REF-0041, REF-0083, REF-0117
Evidence: 1
Label: Bruising

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Cancer (anticancer research)[4]Preliminary · 2/10

inferred from anticancer action

Evidence: 2
Label: Cancer (anticancer research)

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Infection (general)[15]Preliminary · 1/10

inferred from antimicrobial action

Mechanistic Exclude Ids: REF-0041, REF-0083, REF-0117
Evidence: 1
Label: Infection (general)

more plants for infection (general) →detailed sources →

Inflammation (general)[3, 15]Preliminary · 2/10

inferred from anti-inflammatory action

Mechanistic Exclude Ids: REF-0041, REF-0083, REF-0117
Evidence: 2
Label: Inflammation (general)

more plants for inflammation (general) →detailed sources →

Skin irritation[15]Preliminary · 1/10

inferred from anti-inflammatory action

Mechanistic Exclude Ids: REF-0041, REF-0083, REF-0117, REF-0727
Evidence: 1
Label: Skin irritation

more plants for skin irritation →detailed sources →

Swelling / fluid retention[12, 13, 15]Moderate · 5/10

inferred from diuretic action

Mechanistic Exclude Ids: REF-0117
Evidence: 5
Label: Swelling / fluid retention

more plants for swelling / fluid retention →detailed sources →

Urinary support[12, 13, 15]Moderate · 5/10

inferred from diuretic action

Mechanistic Exclude Ids: REF-0117
Evidence: 5
Label: Urinary support

more plants for urinary support →detailed sources →

Urinary tract infection (UTI)[12, 13, 15]Moderate · 5/10

inferred from diuretic action

Mechanistic Exclude Ids: REF-0117
Evidence: 5
Label: Urinary tract infection (UTI)

more plants for urinary tract infection (uti) →detailed sources →

Wounds[13, 15]Preliminary · 1/10

inferred from antimicrobial action

Mechanistic Exclude Ids: REF-0041, REF-0117
Evidence: 1
Label: Wounds

more plants for wounds →detailed sources →

Traditional Use & History

Field horsetail has a long European folk history as a diuretic remedy for urinary gravel and mild fluid retention, as an astringent, anti-inflammatory and vulnerary herb for wounds and connective-tissue support, and, owing to its very high silica content, as a traditional tonic for hair, nails and skin.[12]

Preparations

Decoction/infusion[12]

Dried sterile stem simmered or infused in hot water as a traditional diuretic and connective-tissue-support tea.

Dosage

Decoction/infusion[13]

The EU herbal monograph gives a single dose of 1-4 g of the comminuted herb in 150 mL of boiling water as an infusion or decoction (5-15 minutes), 3-4 times daily, for a daily dose of 3-12 g, in adolescents, adults and elderly; traditionally used over a period of 2 to 4 weeks. For cutaneous use, 10 g in 1 L of water as a decoction for impregnated dressings and irrigation. Not recommended under 12 years. Educational reference only, not a prescription.

Safety, Cautions & Contraindications

Safety note[12, 13, 14, 15, 16]Caution

Field horsetail contains thiaminase, an enzyme that degrades thiamine (vitamin B1); prolonged or excessive use can cause thiamine deficiency - symptoms include neurological problems and weight loss. This risk is greatest with repeated large doses or prolonged use. The plant also contains nicotine at low levels and silica compounds. Not recommended for children or during pregnancy and breastfeeding. People with impaired kidney function should avoid use, as diuretic effects may worsen fluid and electrolyte imbalance. Caution with concurrent diuretic medications. The EMA herbal monograph recognises traditional use at appropriate short-term doses in adults only (European Medicines Agency, 2016; Sandhu et al., 2010).

Safety note[12, 13, 14, 15, 16, 17]Caution

Duke (2002) rates horsetail as + (moderate caution) and notes clinical evidence (score 2) for its diuretic and wound-healing (vulnerary) activities, consistent with Commission E approval. High silica content may strengthen connective tissue, hair, and nails. Dose: 6 g dried herb daily as tea or in capsules. Horsetail contains thiaminase (breaks down vitamin B1) and an unidentified neurotoxin - it should not be taken long-term or in large quantities. Not for use in patients with edema due to cardiac or renal insufficiency, and avoid in children under 12 (Duke, 2002).

Dangerous Lookalikes

Equisetum Palustre[18, 19, 20]Dangerous
Confused Part: Sterile green stems gathered and dried for horsetail tea; toxic marsh horsetail looks very similar and grows in the same damp ground.
Confusion Context: Field horsetail (Equisetum arvense) is gathered for horsetail tea, but horsetails are notoriously hard to tell apart, and marsh horsetail (Equisetum palustre) - one of the most poisonous plants of wet grasslands - grows in the same damp habitat and looks very similar. Marsh horsetail contains the alkaloids palustrine and palustridiene plus high thiaminase (which destroys vitamin B1); it is a well-known livestock poison, and peer-reviewed work stresses that medicinal horsetail must be properly authenticated and differentiated from the more toxic marsh horsetail, which can adulterate herbal material. Because the species are so alike, unverified wild horsetail is a real hazard.
Distinguishing Features: Branch teeth: marsh horsetail (the toxic one) has 5-6 teeth on each branch sheath that lie flat (appressed) against the branch. Broad, spreading teeth in threes or fours indicate a non-toxic horsetail rather than marsh horsetail., Branches solid vs hollow: marsh horsetail has hollow branches, whereas field horsetail's branches are solid. A hollow first branch segment is a warning sign., First branch segment vs sheath: on marsh horsetail the lowest segment of each side branch is short - shorter than or about equal to the stem sheath it emerges from. A first branch segment clearly longer than the sheath indicates it is NOT marsh horsetail. Marsh horsetail also favours wet, marshy ground and fens.
Key Test: Because horsetails are so alike and marsh horsetail is poisonous, only use wild horsetail if you can positively exclude marsh horsetail (Equisetum palustre): confirm branch sheaths have 3-4 spreading teeth (not 5-6 flat-lying ones), solid (not hollow) branches, and a first branch segment longer than the stem sheath. If you cannot confirm all of these - or the plant grows in wet, marshy ground - do not use it.
Reviewed By: Omnia Sana (owner-authorized)
Reviewed Date: 2026-07-07

Harvest Readiness

[11]

Part: stem
Signals: Cut the green sterile stems in summer, when fully grown - NOT the pale spring fertile shoots.
Basis: traditional
Source Quote: Sterile stems follow shortly after and persist through summer.
Species Confirmed: 1
Notes: PFAF (REF-3253); the medicinal material is the green sterile stems, which persist through summer and are cut in summer/late summer and dried (distinct from the pale spring fertile shoots). Single lineage -> provisional. SAFETY: confirm the species against the more toxic Equisetum palustre (marsh horsetail), which grows in similar damp ground, before gathering - see Dangerous Lookalikes.

External Identifiers

References & Sources

  1. Hegedus, C., Muresan, M., Badale, A., Bombicz, M. and others (2020) 'SIRT1 Activation by Equisetum arvense L. (Horsetail) Modulates Insulin Sensitivity in Streptozotocin Induced Diabetic Rats', Molecules, 25(11), pp. 2541. doi:10.3390/molecules25112541 Preclinical
    https://doi.org/10.3390/molecules25112541
  2. Dragos, D., Gilca, M., Gaman, L., Vlad, A., Iosif, L. et al (2017) 'Phytomedicine in Joint Disorders', Nutrients, 9(1), pp. 70. doi:10.3390/nu9010070 Traditional / reference
    https://doi.org/10.3390/nu9010070
  3. Grundemann, C., Lengen, K., Sauer, B., Garcia-Kaufer, M. and others (2014) 'Equisetum arvense (common horsetail) modulates the function of inflammatory immunocompetent cells', BMC Complementary and Alternative Medicine, 14, pp. 283. doi:10.1186/1472-6882-14-283 Preclinical
    https://doi.org/10.1186/1472-6882-14-283
  4. Wang, L., Zhang, L., Zheng, G. and Luo, H (2021) 'Equisetum arvense L aqueous extract: a novel chemotherapeutic supplement for treatment of human colon carcinoma', Archives of Medical Science, 19(5), pp. 1472-1478. doi:10.5114/aoms/138146 Preclinical
    https://doi.org/10.5114/aoms/138146
  5. Jeong, S.Y., Yu, H.S., Ra, M.J., Jung, S.M. and others (2023) 'Phytochemical Investigation of Equisetum arvense and Evaluation of Their Anti-Inflammatory Potential in TNFalpha/INFgamma-Stimulated Keratinocytes', Pharmaceuticals, 16(10), pp. 1478. doi:10.3390/ph16101478 Preclinical
    https://doi.org/10.3390/ph16101478
  6. Klncalp, S., Ekiz, F., Basar, O., Coban, S. and others (2012) 'Equisetum arvense (Field Horsetail)-induced liver injury', European Journal of Gastroenterology & Hepatology, 24(2), pp. 213-214. doi:10.1097/MEG.0b013e32834e7ff0 Preclinical
    https://doi.org/10.1097/MEG.0b013e32834e7ff0
  7. Maeda, H., Miyamoto, K. and Sano, T (1997) 'Occurrence of dermatitis in rats fed a cholesterol diet containing field horsetail (Equisetum arvense L.)', Journal of Nutritional Science and Vitaminology, 43(5), pp. 553-563. doi:10.3177/jnsv.43.553 Preclinical
    https://doi.org/10.3177/jnsv.43.553
  8. Saslis-Lagoudakis, C.H., Bruun-Lund, S., Iwanycki, N.E., Seberg, O. and others (2015) 'Identification of common horsetail (Equisetum arvense L.; Equisetaceae) using Thin Layer Chromatography versus DNA barcoding', Scientific Reports, 5, pp. 11942. doi:10.1038/srep11942 Preclinical
    https://doi.org/10.1038/srep11942
  9. Mimica-Dukic, N., Simin, N., Cvejic, J., Jovin, E. and others (2008) 'Phenolic compounds in field horsetail (Equisetum arvense L.) as natural antioxidants', Molecules, 13(7), pp. 1455-1464. doi:10.3390/molecules13071455 Preclinical
    https://doi.org/10.3390/molecules13071455
  10. Tufarelli, V., Baghban-Kanani, P., Azimi-Youvalari, S., Hosseintabar-Ghasemabad, B. and others (2021) 'Effects of Horsetail (Equisetum arvense) and Spirulina (Spirulina platensis) Dietary Supplementation on Laying Hens Productivity and Oxidative Status', Animals, 11(2), pp. 335. doi:10.3390/ani11020335 Preclinical
    https://doi.org/10.3390/ani11020335
  11. Plants For A Future 'Equisetum arvense (Field Horsetail)'. Available at: https://pfaf.org/user/Plant.aspx?LatinName=Equisetum+arvense Traditional / reference
    https://pfaf.org/user/Plant.aspx?LatinName=Equisetum+arvense
  12. Carneiro, D.M., Marques, L.C., Velasques, L.O. et al (2016) 'Randomized, double-blind clinical trial to assess the acute diuretic effect of Equisetum arvense (Field Horsetail) in healthy volunteers'. doi:10.1155/2014/760683 Randomized trial
    https://doi.org/10.1155/2014/760683
  13. European Medicines Agency (2016) 'European Union herbal monograph on Equisetum arvense L., herba'. Available at: https://www.ema.europa.eu/en/documents/herbal-monograph/final-european-union-herbal-monograph-equisetum-arvense-l-herba_en.pdf Traditional / reference
    https://www.ema.europa.eu/en/documents/herbal-monograph/final-european-union-herbal-monograph-equisetum-arvense-l-herba_en.pdf
  14. http://LatvijasDaba.lv (n.d.) 'tīruma kosa – Equisetum arvense L'. Available at: http://LatvijasDaba.lv Traditional / reference
    http://LatvijasDaba.lv
  15. Sandhu, N.S., Kaur, S. and Chopra, D (2010) 'Equisetum arvense: pharmacology and phytochemistry — a review', 3(3), pp. 146--150. Traditional / reference
    https://scholar.google.com/scholar?q=Equisetum%20arvense%3A%20pharmacology%20and%20phytochemistry%20%E2%80%94%20a%20review
  16. Royal Botanic Gardens, Kew (n.d.) 'Equisetum arvense L'. Available at: https://powo.science.kew.org/taxon/urn:lsid:http://ipni.org:names:17003330-1 Traditional / reference
    https://powo.science.kew.org/taxon/urn:lsid:http://ipni.org:names:17003330-1
  17. Duke, J.A (2002) 'Handbook of Medicinal Herbs, Second Edition'. Traditional / reference
    https://scholar.google.com/scholar?q=Handbook%20of%20Medicinal%20Herbs%2C%20Second%20Edition
  18. NatureSpot 'Marsh Horsetail - Equisetum palustre'. Available at: https://www.naturespot.org/species/marsh-horsetail Traditional / reference
    https://www.naturespot.org/species/marsh-horsetail
  19. Muller, J. and Puttich, P.M. and Beuerle, T (2020) 'Variation of the Main Alkaloid Content in Equisetum palustre L. in the Light of Its Ontogeny', Toxins, 12(11), pp. 710. doi:10.3390/toxins12110710 Preclinical
    https://doi.org/10.3390/toxins12110710
  20. Ibi, A. and Du, M. and Beuerle, T. and Melchert, D. and Solnier, J. and Chang, C (2022) 'A Multi-Pronged Technique for Identifying Equisetum palustre and Equisetum arvense - Combining HPTLC, HPLC-ESI-MS/MS and Optimized DNA Barcoding Techniques', Plants, 11(19), pp. 2562. doi:10.3390/plants11192562 Preclinical
    https://doi.org/10.3390/plants11192562

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Educational use only. This profile summarises traditional and scientific sources for reference. It is not medical advice and not a substitute for a qualified practitioner. Some plants carry safety cautions and drug interactions - always check before use.
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