Quick Summary
Horsetail (Equisetum arvense) is a plant traditionally used in herbal medicine for various purposes, including urinary tract support, wound healing, and hair health. Research evidence for its clinical efficacy is limited and variable, with some positive findings in herbal combinations addressing urinary symptoms and demonstrating good tolerability. More rigorous clinical studies are needed to confirm its therapeutic benefits and safety profile.
What is it?
Horsetail is a perennial plant found in many parts of the world belonging to the genus Equisetum. It has been used in traditional herbal medicine for centuries, valued primarily for its perceived diuretic and wound-healing properties. The plant contains silica and other compounds thought to contribute to its medicinal effects.
Traditional Uses
- Support for urinary tract health, including treating symptoms of overactive bladder and incontinence
- Wound healing and dermatological applications
- Supporting hair health
- Possible anti-inflammatory effects in joint disorders
Active Compounds
Horsetail contains various bioactive constituents, including:
- Silica (silicon dioxide)
- Flavonoids
- Saponins
- Alkaloids
- Tannins
Potential Benefits with Evidence Levels
- Reduction of symptoms of overactive bladder and urinary incontinence: Moderate evidence from a randomized, double-blind, placebo-controlled phase 2 clinical trial of a proprietary herbal combination containing Equisetum arvense showed significant symptom improvement and good tolerability (Schoendorfer et al. 2018).
- Potential supportive use in joint disorders (anti-inflammatory and symptom relief): Low to moderate evidence from systematic reviews of herbal therapies in joint disorders cites Equisetum arvense among plants explored; however, direct human clinical trials specific to horsetail are limited (Dragos et al. 2017; Allam et al. 2025).
- Traditional use in wound healing and dermatological conditions: Traditional and ethnopharmacological data support its use, with some in vitro and animal model evidence; no high-quality human clinical trials confirming efficacy are currently available.
Side Effects
Horsetail-containing herbal products were generally well tolerated in clinical trials, with no significant side effects leading to treatment discontinuation reported in the main available randomized controlled trial. Reported adverse effects were minimal and not significantly different from placebo. Due to limited detailed data, caution is advised when using horsetail, particularly with prolonged use.
Drug Interactions
There is no high-quality clinical evidence specifically documenting herb-drug interactions with horsetail. However, general concerns exist regarding herb-drug interactions with herbal supplements. Increased awareness and caution are recommended when combined with other medications (Babos et al. 2021).
Who Should Avoid It
- Individuals with known hypersensitivity or allergy to horsetail or its components
- Pregnant or breastfeeding women, due to insufficient evidence on safety during these periods; use is generally advised against unless supervised by a healthcare professional
- People with medical conditions or who are taking medications should consult healthcare providers before use
Evidence Limitations
The current evidence base for horsetail is limited by the scarcity of high-quality human clinical trials specifically assessing horsetail alone. Most data derive from herbal combinations or traditional use reports. Sample sizes in studies have been small, outcomes heterogeneous, and long-term safety not well established. Further large-scale, rigorous randomized controlled trials are needed to better define efficacy, safety, and appropriate dosing guidelines.
References
- Schoendorfer N, Sharp N, Seipel T, Schauss AG, Ahuja KDK. Urox containing concentrated extracts of Crataeva nurvala stem bark, Equisetum arvense stem and Lindera aggregata root, in the treatment of symptoms of overactive bladder and urinary incontinence: a phase 2, randomised, double-blind placebo controlled trial. 2018. DOI: 10.1186/s12906-018-2101-4
- Dragos D, Gilca M, Gaman L, Vlad A, Iosif L, Stoian I, Lupescu O. Phytomedicine in Joint Disorders. 2017. DOI: 10.3390/nu9010070
- Allam AT, El-Shiekh RA, El-Dessouki AM, et al. Pathophysiology, conventional treatments, and evidence-based herbal remedies of hair loss with a systematic review of controlled clinical trials. 2025. DOI: 10.1007/s00210-025-04286-6
- Babos MB, Heinan M, Redmond L, et al. Herb-Drug Interactions: Worlds Intersect with the Patient at the Center. 2021. DOI: 10.3390/medicines8080044
Last Reviewed
June 2024
Informational Disclaimer
This page is for informational purposes only and does not constitute medical advice. The efficacy and safety of horsetail supplements have not been fully established. Always consult your healthcare provider before starting any new herbal product, particularly if you are pregnant, nursing, have existing health conditions, or are taking other medications.