# Field Horsetail (Equisetum arvense)

**Canonical URL:** https://ingredients.hermeticasuperfoods.com/ingredients/field-horsetail
**Data Source:** Hermetica Superfoods Ingredient Encyclopedia
**Updated:** 2026-03-19
**Evidence Score:** 6 / 10
**Category:** European
**Also Known As:** Equisetum arvense, Common Horsetail, Bottle Brush, Scouring Rush, Mare's Tail, Snake Grass, Puzzlegrass, Pewterwort

## Overview

Field horsetail (Equisetum arvense) is a European medicinal plant containing silica and phenolic compounds that may support vascular health and blood clotting. Its antioxidant properties stem from DPPH radical scavenging activity and [lipid peroxidation](/ingredients/condition/antioxidant) inhibition mechanisms.

## Health Benefits

• [Antioxidant activity](/ingredients/condition/antioxidant) demonstrated through in vitro DPPH radical scavenging and lipid peroxidation inhibition (preliminary evidence only)
• Potential vasorelaxant properties attributed to phenolic compounds (mechanism-based claim, no clinical evidence)
• Hemostatic (blood-clotting) support traditionally claimed by herbalists (traditional use only, no clinical trials)
• High mineral content including silica, calcium, and trace elements may support tissue health (compositional data only)
• Limited evidence base - no human clinical trials available in provided research

## Mechanism of Action

Field horsetail's phenolic compounds, including quercetin and kaempferol derivatives, exhibit [antioxidant activity](/ingredients/condition/antioxidant) by scavenging DPPH free radicals and inhibiting lipid peroxidation in cell membranes. The plant's vasorelaxant properties are attributed to phenolic compounds that may modulate nitric oxide pathways in vascular smooth muscle. Silica content contributes to connective tissue support through [collagen synthesis](/ingredients/condition/skin-health) enhancement.

## Clinical Summary

Current evidence for field horsetail is limited to preliminary in vitro studies demonstrating [antioxidant activity](/ingredients/condition/antioxidant) through DPPH radical scavenging assays and lipid peroxidation inhibition tests. No randomized controlled trials have been conducted to evaluate clinical efficacy in humans. Traditional use supports hemostatic properties, but this remains unvalidated by modern clinical research. The vasorelaxant claims are based solely on mechanism-based evidence without human studies.

## Nutritional Profile

Field Horsetail (Equisetum arvense) is notable primarily for its exceptionally high silica (silicon dioxide) content, ranging from 5–8% of dry weight, making it one of the richest plant sources of this mineral; silicon is present largely as monosilicic acid and silica polymers, with bioavailability enhanced by aqueous extraction (tea/decoction). Mineral profile includes potassium (approximately 2–3% dry weight), calcium (approximately 0.2–0.5% dry weight), magnesium, manganese, and iron in moderate trace amounts. Protein content is low, approximately 2–5% dry weight, with limited nutritional significance. Carbohydrates constitute the majority of dry mass (~60–70%), primarily structural polysaccharides including equisetumosides and pectin-like compounds, contributing modest dietary fiber. Fat content is negligible (<1% dry weight). Bioactive compounds include phenolic acids (caffeic acid, ferulic acid, protocatechuic acid at approximately 0.1–0.5 mg/g dry weight collectively), flavonoids including kaempferol, quercetin, and isoquercitrin (approximately 0.2–0.8% total flavonoids by dry weight), and the alkaloid nicotine in trace amounts (<0.001% dry weight). The phytosterol content includes beta-sitosterol at low concentrations. Vitamin content is limited but includes small amounts of vitamin C (ascorbic acid, approximately 5–10 mg/100g fresh weight) and trace vitamin K. Chlorophyll pigments are present in the green aerial parts. Thiaminase enzyme is present in raw plant material and can degrade vitamin B1 (thiamine), which is nutritionally significant for safety; this enzyme is inactivated by drying or heat. Tannin content ranges approximately 5–8% dry weight (hydrolyzable and condensed forms), reducing overall mineral bioavailability when consumed in high quantities. Silicon bioavailability from aqueous infusions is estimated at 30–50% of total silicon content, substantially higher than from whole dried plant material.

## Dosage & Preparation

No clinically studied dosage ranges for human use are available in the provided research. The European Medicines Agency mentions a pharmacopoeial standard requiring minimum 0.3% total flavonoids for standardization, but specific therapeutic dosing protocols are not detailed. Consult a healthcare provider before starting any new supplement.

## Safety & Drug Interactions

Field horsetail is generally well-tolerated but may cause digestive upset in sensitive individuals. The plant contains trace amounts of nicotine-like alkaloids, which could theoretically interact with medications affecting the nervous system. Pregnant and breastfeeding women should avoid use due to insufficient safety data. Long-term use may theoretically deplete thiamine (vitamin B1) due to thiaminase enzyme content in some Equisetum species.

## Scientific Research

The available research consists primarily of phytochemical analyses and in vitro [antioxidant](/ingredients/condition/antioxidant) studies, with no human clinical trials, randomized controlled trials, or meta-analyses present in the provided sources. The research dossier explicitly notes the absence of peer-reviewed clinical trial data with specific PMIDs.

## Historical & Cultural Context

While herbalists have recommended field horsetail as a hemostatic agent, the provided research does not detail specific traditional medicine systems or historical timeframes. The sources do not provide historical context regarding its use in Ayurvedic, Traditional Chinese Medicine, or European herbalism.

## Synergistic Combinations

Vitamin C, biotin, bamboo extract, nettle leaf, collagen peptides

## Frequently Asked Questions

### How much silica does field horsetail contain?

Field horsetail typically contains 5-8% silica by dry weight, making it one of the highest natural plant sources of bioavailable silica. This silica content contributes to its traditional use for connective tissue support.

### Can field horsetail help with hair and nail growth?

While traditional use suggests benefits for hair and nails due to silica content supporting collagen synthesis, no clinical trials have confirmed these effects. The silica may theoretically support keratin production in hair and nail structures.

### What is the difference between field horsetail and other horsetail species?

Field horsetail (Equisetum arvense) is the most commonly used medicinal species and has the highest silica content. Other species like Equisetum hyemale contain higher levels of potentially toxic alkaloids and are not recommended for internal use.

### How should field horsetail be taken for maximum benefits?

Traditional preparations include teas using 2-3 grams of dried herb steeped for 10-15 minutes, or standardized extracts providing 300-600mg daily. Taking with vitamin C may enhance silica absorption, though optimal dosing lacks clinical validation.

### Does field horsetail interact with blood thinning medications?

Field horsetail may theoretically enhance blood clotting due to traditional hemostatic use, potentially opposing anticoagulant medications like warfarin. Patients on blood thinners should consult healthcare providers before use, though specific interactions are not well-documented.

### Is field horsetail safe during pregnancy and breastfeeding?

Field horsetail is not recommended during pregnancy or breastfeeding due to insufficient safety data and its traditional use as a diuretic, which may affect fluid balance. Pregnant and nursing women should consult a healthcare provider before use, as the high mineral content and bioactive compounds have not been adequately studied in these populations.

### What is the difference between field horsetail extract and whole herb tea?

Field horsetail extract (typically standardized for silica content) provides concentrated bioactive compounds in a smaller dose, while whole herb tea offers a milder, broader spectrum of minerals and phytochemicals with lower bioavailability. Extracts generally deliver more consistent silica levels per dose, whereas tea preparations rely on proper steeping time to extract minerals effectively.

### What does current clinical research show about field horsetail's antioxidant benefits?

Laboratory studies (in vitro) have demonstrated that field horsetail exhibits antioxidant activity through mechanisms like DPPH radical scavenging and lipid peroxidation inhibition, but these findings have not been confirmed in human clinical trials. Current evidence remains preliminary, and more rigorous human studies are needed to establish whether these antioxidant effects translate to measurable health benefits in supplementation.

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