Using Horsetail Herb

Annette McDermott
Reviewed by Terri Forehand RN
Horsetail herb

Horsetail herb, also known as scouring rush or Pewterwort, has been used for centuries as an herbal remedy and household helper. Horsetail gets its name from its long, whorled branches that look similar to a horse's tail. Horsetail is commonly found around water, but it may also be found in dry areas such as meadows or fields.

Types of Horsetail

Horsetail is a non-flowering, perennial herb with hollow stems. There are many species of horsetail growing wild throughout the world. Some are used for medicinal purposes while others are strictly ornamental. According to the Encyclopedia Britannica, the following types of horsetail are commonly found in North America, each with distinct characteristics:

  • Common Horsetail (Equisetum arvense): Found primarily around water in North America and Eurasia, this species of horsetail grows to be about one foot tall and has thick, whorled branches encircling each shoot.
  • Wood Horsetail (Equisetum sylvaticum): Found primarily in damp areas in the woods, this horsetail species has more fragile branches than its common counterpart.
  • Variegated Horsetail (Equisetum variegatum): This form of horsetail is easily recognizable by its evergreen appearance and black sheath markings.
  • Common Scouring Rush (Equisetum hyemale): Usually found along riverbanks, this species of horsetail grows very tall and evergreen. This form was used throughout history to scour pots and pans, especially pewter, and some people still use the silica-rich herb today as a natural way to clean cookware or sand wood.
  • Giant Horsetail (Equisetum praealtum): This evergreen horsetail is found in North America and Asia and grows to almost 12 feet tall.

Potential Health Benefits of Horsetail

Using horsetail herb as a natural remedy dates back to ancient Greek and Roman civilizations. Horsetail is rich in silicon, a mineral believed to have positive health effects. The University of Maryland Medical Center (UMM) states that although few studies have been performed on the health benefits of horsetail, there are some potential positive health results of using the herb.

Fights Osteoporosis

In a study mentioned in the same UMM report, 122 Italian women took horsetail twice daily. The results of the study determined that the herb may improve bone density. The women in the study took either horsetail dry extract alone or a calcium/horsetail combination. Both groups showed improved bone density.

Antioxidant Source

The National Institute's of Health (PubMed) cites an abstract on their website which concludes that horsetail extract is a good source of phytochemicals and antioxidants.

Fights Bacteria

Horsetail is believed to fight bacteria and have powerful healing properties. An abstract on PubMed states that studies show horsetail essential oil has strong antimicrobial effects against dangerous bacteria strains such as Staphylococcus, E. Coli, Salmonella, and Candida.

Diuretic

One of the most common uses of horsetail is to relieve water retention. However, the National Institutes of Health (MedLine Plus) states that although plants closely related to horsetail increase urine output, there is no direct evidence that horsetail has this effect.

May Treat Urinary Problems

Due to its high antimicrobial properties, horsetail is often prescribed by herbalists to treat urinary tract and bladder infections, as well as kidney stones. Since studies show horsetail fights some of the bacteria strains that cause urinary tract infections such as E. Coli, it's feasible that this herb may effectively treat them. However, more research is needed to prove this theory.

Promotes Hair Growth

The high silicone content in horsetail may help strengthen hair and prevent breakage, which may lead to increased hair growth.

Potential Side Effects of Using Horsetail

Common horsetail is generally believed to be safe to use, but as with any herbal remedy, there is a risk of side effects. Since horsetail is not well studied, it's critical to use the herb under the supervision of a doctor or certified herbalist and avoid it altogether if you are pregnant or breastfeeding. UMM and Medline Plus offer the following precautions when using horsetail herb:

Drops Thiamin Levels

Horsetail contains a chemical that breaks down thiamin in the body. As a result, prolonged use of horsetail may cause thiamin (vitamin B1) levels in the body to drop. In addition, do not drink alcohol or use the herb areca while taking horsetail since both may also cause a drop in thiamin levels.

Diuretic

The diuretic effects of horsetail may cause low potassium levels which can lead to dangerous heart arrythmias. Do not use horsetail if you have a history of heart arrythmias, or if you are taking the drug Digoxin or a diuretic.

Caffeine Sensitivity

Horsetail contains caffeine and should not be used if you are sensitive to caffeine or are using nicotine patches or gum. Some manufacturers produce caffeine free horsetail tea bags for people with caffeine sensitivity.

Lithium Build-Up

Do not use horsetail if you take lithium, a drug commonly used to treat bipolar disorder. Horsetail may prevent the body from ridding itself of lithium, leading to a dangerous build-up of the drug.

Alters Blood Sugar Levels

Horsetail may alter blood sugar levels and should not be used if you have diabetes or low blood sugar, or take medications that affect blood sugar levels.

Accidental Poisoning

Common horsetail (Equisetum arvense) is sometimes confused with a similar plant, Equisetum palustre. Equisetum palustre is poisonous to horses and cattle, and it should never be used by humans.

Chromium Poisoning

Horsetail contains chromium. To avoid the risk of chromium poisoning, you should not combine chromium supplements or products that contain chromium, such as brewer's yeast or bilberry, with horsetail.

How to Use Horsetail

Horsetail is available in various forms, including a dried herb, capsules, tincture, or tea. To avoid possible contamination, only purchase horsetail from trusted, reputable sources. Due to its nicotine content and potential side effects, horsetail is not recommended for pediatric use; however, UMM suggests the following adult doses:

  • Capsule: 300 mg, 3 times daily, standardized to contain 10 - 15% silica
  • Herbal Tea: 2 - 3 teaspoonfuls, 3 times daily. Pour hot water onto herb and steep for 5 - 10 minutes.
  • Tincture (1:5): 1 - 4 ml, 3 times daily
  • External Compress: 10 g of herb per 1 liter water daily

A Versatile Herb

There's good reason ancient civilizations used horsetail as a natural remedy; it's an easily obtained herb that offers strong medicinal benefits. In addition, the herb is a beautiful ornamental plant to grow around a backyard fish pond or water garden, and you can even use horsetail as a kitchen tool to scour your cookware. However, as with any herbal remedy, it contains strong ingredients and should be used with caution, especially if you have an underlying medical condition or take prescription or over-the-counter medications. Seek the advice of your physician before use.

Using Horsetail Herb