Horsetail Herb: Potential Benefits, Uses, and Safety Guide

Horsetail herb has been valued in traditional medicine for thousands of years, with practitioners using it to support bone health, promote wound healing, and enhance the appearance of hair, skin, and nails. While this ancient fern continues to gain popularity as a natural remedy, understanding its potential benefits and limitations is essential for safe use.

This comprehensive guide explores what science says about horsetail benefits, how to use this herb safely, and important precautions you should know before adding it to your wellness routine.

What Is Horsetail Herb?

Horsetail (Equisetum arvense), also known as horse tail herb or field horsetail, is a perennial fern that belongs to one of the oldest plant families on Earth. This distinctive plant has survived relatively unchanged for millions of years and grows naturally throughout North America, Europe, and other temperate regions worldwide.

The plant is easily recognized by its unique appearance, featuring hollow, jointed stems with whorls of thin, needle-like branches that resemble a horse’s tail—hence its common name. Horsetail thrives in moist environments such as riverbanks, meadows, and wetlands, growing from spring through fall.

Key Active Compounds

What makes horsetail herb particularly interesting from a health perspective is its unique nutritional profile:

• Silica: Horsetail contains the highest concentration of silica among all plants, with up to 25% of its dry weight being this mineral. Silica plays a crucial role in connective tissue formation and may support bone, skin, hair, and nail health.
• Antioxidants: The herb is rich in flavonoids and phenolic compounds that help protect cells from oxidative stress and free radical damage.
• Minerals: Contains potassium, manganese, and calcium in notable amounts.
• Other compounds: Includes saponins, alkaloids, and various plant sterols.

Horsetail Benefits: What Does Research Show?

While horsetail has been used traditionally for numerous health purposes, scientific research is still emerging. Here’s what current evidence suggests about potential horsetail benefits:

May Support Bone Health and Density

One of the most promising areas of horsetail research involves bone health. The high silica content in horsetail appears to influence bone metabolism in several ways.

Bones undergo constant remodeling through two types of cells: osteoblasts (which build bone) and osteoclasts (which break down bone). Maintaining the right balance between these processes is essential for strong, healthy bones.

Laboratory studies suggest that horsetail extract may help stimulate osteoblast activity while inhibiting excessive osteoclast function. This could potentially benefit people with osteoporosis, a condition characterized by weak, brittle bones due to excessive bone breakdown.

Animal research has shown promising results, with studies finding that horsetail extract supplementation led to improved bone density compared to control groups. The silica in horsetail may enhance collagen synthesis and improve calcium absorption—both critical factors for maintaining bone strength and integrity.

However, it’s important to note that human clinical trials are still limited, and more research is needed to confirm these bone-protective effects in people.

Acts as a Natural Diuretic

Horsetail has traditionally been used as a natural diuretic—a substance that increases urine production and helps the body eliminate excess fluid. This property has made it a popular folk remedy for urinary tract concerns and fluid retention.

A small clinical study involving healthy men found that horsetail extract produced a significant diuretic effect, comparable to conventional diuretic medications. Researchers attributed this effect to the herb’s high concentration of antioxidants and mineral salts.

Some traditional uses suggest horsetail may help with:

• Urinary tract health and function
• Reducing fluid retention
• Supporting kidney health
• Managing mild urinary incontinence symptoms

A comprehensive review examined horsetail’s potential for various urinary conditions, including urinary tract inflammation and kidney stones, finding preliminary evidence of benefit. However, researchers emphasized that more robust clinical trials are necessary before making definitive recommendations.

Promotes Wound Healing

The topical application of horsetail ointment shows promise for wound healing, likely due to its silica content and anti-inflammatory properties.

In a clinical study involving postpartum women recovering from episiotomy (a surgical incision made during childbirth), applying a 3% horsetail extract ointment significantly accelerated wound healing compared to standard care. Participants experienced reduced pain, swelling, redness, and discharge.

Animal studies have reinforced these findings, with rats treated with horsetail ointments showing wound closure rates of 95-99% and enhanced skin tissue regeneration.

The mechanisms behind these effects may include:

• Enhanced collagen production due to silica content
• Anti-inflammatory action that reduces tissue damage
• Antioxidant properties that protect healing tissues
• Antimicrobial effects that may prevent infection

Supports Hair Growth and Strength

Many people turn to horsetail herb for its potential hair benefits. The combination of silica and antioxidants may support healthier, stronger hair in several ways.

Silica is naturally present in hair fibers and appears to influence hair quality. Research suggests that higher silicon content in hair correlates with lower hair loss rates and increased shine. Meanwhile, antioxidants help protect hair follicles from oxidative stress and inflammation that can contribute to hair aging and loss.

Clinical studies examining supplement blends containing horsetail extract have shown improvements in hair growth, volume, and thickness among women with self-perceived hair thinning. However, because these studies used combination products, it’s difficult to determine how much benefit came specifically from horsetail versus other ingredients.

More research focusing solely on horsetail’s effects on hair health would help clarify its true potential for promoting hair growth and reducing hair loss.

May Benefit Nail Health

The same silica that potentially benefits bones and hair may also strengthen nails. Some research has explored horsetail extract in nail treatments, particularly for managing nail psoriasis—a condition that causes nail deformities, pitting, and discoloration.

Studies examining nail lacquers containing horsetail extract combined with other nail-hardening agents found reductions in nail psoriasis symptoms. While these results are encouraging, additional research is needed to understand horsetail’s specific contribution to nail health.

Other Potential Benefits

Preliminary research suggests horsetail may offer additional health benefits:

• Anti-inflammatory effects: Laboratory studies indicate that horsetail extract may inhibit certain immune cells involved in inflammatory responses, potentially offering benefits for inflammatory conditions.
• Antimicrobial properties: Horsetail essential oil has demonstrated activity against various bacteria and fungi in test-tube studies, including Staphylococcus aureus, E. coli, and Candida albicans.
• Blood sugar regulation: Animal and laboratory research suggests horsetail extract might help lower blood sugar levels and support pancreatic health, though human studies are lacking.
• Antioxidant protection: The herb’s rich phenolic compound content provides potent antioxidant activity that may protect against cellular damage.

It’s crucial to remember that many of these benefits have only been studied in laboratory settings or animal models. Human clinical trials are necessary to confirm whether horsetail provides these same benefits when consumed by people.

How to Use Horsetail Herb

Horsetail is available in several forms, each with different uses and preparation methods:

Horsetail Tea

The most traditional way to consume horsetail is as a tea made from dried herb. To prepare:

• Use 1-2 teaspoons of dried horsetail herb per cup of hot water
• Steep for 5-10 minutes
• Strain and drink up to 2-3 cups daily

Capsules and Tablets

Standardized horsetail extract capsules offer consistent dosing. Studies have used doses ranging from 300-900 mg daily, though an optimal dose hasn’t been established through clinical research.

Tinctures

Liquid extracts or tinctures provide a concentrated form of horsetail. Follow manufacturer instructions for dosing, as potency varies between products.

Topical Applications

For wound healing or skin benefits, look for ointments or creams containing horsetail extract. Studies have used concentrations of 3-10% horsetail extract in topical formulations.

Dosage Recommendations

Currently, there is no standardized recommended dosage for horsetail herb, as research is still limited. The European Medicines Agency suggests a maximum daily dose of 900 mg for dry extracts.

If you’re considering using horsetail, start with the lowest effective dose and consult with a healthcare provider, especially if you have existing health conditions or take medications.

Horsetail Side Effects and Safety Concerns

While horsetail is generally considered safe when used appropriately for short periods, there are important safety considerations to keep in mind.

Thiaminase Content

Horsetail contains an enzyme called thiaminase, which breaks down thiamine (vitamin B1). Long-term use of horsetail could potentially lead to vitamin B1 deficiency, particularly in people who already have low thiamine levels.

People at higher risk for thiamine deficiency include those with alcohol use disorder, certain digestive conditions, and those taking medications that interfere with thiamine absorption.

Nicotine Content

Horsetail contains small amounts of nicotine. While the levels are low, people with nicotine allergies or those trying to quit smoking may want to avoid this herb.

Potential Drug Interactions

Horsetail may interact with certain medications, including:

• Antiretroviral drugs: Used for HIV treatment
• Diuretic medications: Could enhance their effects, leading to excessive fluid loss
• Diabetes medications: May affect blood sugar levels
• Lithium: Horsetail’s diuretic effect could alter lithium levels in the body

Always inform your healthcare provider about all supplements you’re taking, including herbal remedies like horsetail.

Kidney Disease Concerns

People with kidney disease should avoid horsetail, as it may cause potassium levels to become dangerously high. The herb’s diuretic properties could also strain already compromised kidney function.

Reported Adverse Effects

While rare, some adverse effects have been reported with horsetail use:

• Digestive upset
• Increased urination
• In one documented case, a woman developed pancreatitis (pancreatic inflammation) after drinking horsetail tea regularly, though her symptoms resolved after discontinuing use

Who Should Avoid Horsetail?

The following groups should not use horsetail herb:

• Pregnant and breastfeeding women (safety hasn’t been established)
• People with kidney disease or impaired kidney function
• Individuals with thiamine deficiency or at risk for it
• Those with nicotine allergies
• People taking antiretroviral medications
• Children (insufficient safety data)

Choosing Quality Horsetail Products

Since the FDA doesn’t regulate herbal supplements the same way as medications, product quality can vary significantly. Here are tips for selecting high-quality horsetail products:

• Look for third-party testing: Choose products tested by independent organizations like USP, NSF International, or ConsumerLab
• Check for standardization: Products standardized for silica content ensure consistent dosing
• Verify the species: Ensure the product contains Equisetum arvense, as some horsetail species contain toxic compounds
• Read labels carefully: Avoid products with unnecessary fillers or additives
• Research the manufacturer: Choose reputable companies with good manufacturing practices

The Bottom Line on Horsetail Benefits

Horsetail herb has a long history of traditional use for supporting bone, skin, hair, nail, and urinary tract health. Its high silica content and antioxidant properties provide a theoretical basis for many of these traditional uses.

Current research shows promising preliminary evidence for several horsetail benefits, particularly related to bone health, wound healing, and diuretic effects. However, most studies are small, short-term, or conducted in laboratory settings rather than humans. More robust clinical trials are needed to confirm the herb’s effectiveness and establish optimal dosing guidelines.

While horsetail appears relatively safe for short-term use in healthy adults, it’s not without risks. The herb can interact with medications, may deplete thiamine with long-term use, and isn’t appropriate for everyone—particularly pregnant women, people with kidney disease, and those with certain health conditions.

If you’re considering using horsetail herb for any health purpose, consult with a qualified healthcare provider first. They can help you weigh the potential benefits against any risks based on your individual health status and medications, ensuring you make an informed decision about whether this ancient remedy is right for you.

Remember that herbal supplements like horsetail should complement, not replace, conventional medical care. They work best as part of a comprehensive approach to health that includes a balanced diet, regular exercise, adequate sleep, and appropriate medical treatment when needed.

Sources:

• National Center for Biotechnology Information – Horsetail Health Effects
• PubMed Central – Equisetum arvense Review
• PubMed Central – Horsetail Biological Activities
• PubMed Central – Diuretic Effect of Horsetail
• PubMed Central – Horsetail for Kidney Conditions
• European Medicines Agency – Herbal Medicine Guidelines
• National Institutes of Health – Office of Dietary Supplements