Herbs (Global Traditional) · European
Field Horsetail (Equisetum arvense) (Equisetum arvense)
Moderate Evidencebotanical
Hermetica Superfood Encyclopedia
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 inhibition mechanisms.
Field horsetail (Equisetum arvense) is a perennial plant native to temperate regions of the Northern Hemisphere, with the aerial sterile stems used medicinally. The herb is traditionally prepared as extracts, infusions, or dried powder, containing 5-7.7% silicic acid and meeting pharmacopoeial standards of minimum 0.3% total flavonoids.
The available research consists primarily of phytochemical analyses and in vitro 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.
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.
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.
Field horsetail's phenolic compounds, including quercetin and kaempferol derivatives, exhibit antioxidant activity 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 enhancement.
Current evidence for field horsetail is limited to preliminary in vitro studies demonstrating antioxidant activity 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.
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.
