Overview: 

Horsetail (Equisetum arvense) is an herbal remedy dating back to at least ancient Roman and Greek medicine. It was used traditionally to stop bleeding, heal ulcers and wounds, and treat tuberculosis and kidney problems. The name Equisetum is derived from the Latin roots equus, meaning "horse," and seta, meaning "bristle." 

Horsetail contains silicon, which plays a role in strengthening bone. For that reason, it is sometimes suggested  as a treatment for osteoporosis. It  is also used as a diuretic,  and as an ingredient in come cosmetics. However, very few studies have looked at horsetail's effect in humans. 

Plant Description: 

Horsetail  is descended from huge, tree-like plants that thrived 400 million years ago during  the Paleozoic era. A close relative  of the fern, horsetail is a non-flowering weed found throughout parts  of Europe, Asia, the Middle East, and North America. The plant is a perennial (returns each year) with hollow stems and shoots that look like asparagus at first. As the plant dries, silica crystals that form  in the stems and branches look like feathery tails and give the plant a scratching effect. That accounts for its historic use in polishing metal, particularly pewter. 

Parts Used: 

The aboveground parts of horsetail (fresh or dried) are used for medicinal purposes. 

Medicinal Uses  and Indications: 

Very few studies have been done of horsetail's effect in humans. Horsetail  has traditionally been used as a diuretic (helps rid the body of excess fluid by increasing urine output). One study examined the use of horsetail by people who had  a history of uric acid kidney stones. The people who took horsetail did see an increase in diuresis (urine output). 

Osteoporosis 

Horsetail has been suggested as a treatment for osteoporosis (thinning bone), because it contains silicon, a mineral needed for bone health. However, only one study has examined  horsetail for osteoporosis. In  that study, 122 Italian women took  horsetail dry extract or Osteosil calcium 270 mg twice daily (a horsetail-calcium combination used in Italy for osteoporosis and fractures). Although both groups who took horsetail did improve bone density,  the study was poorly designed.  More research is needed to see whether horsetail has any effect on bone density. 

Other Indications

Horsetail is sometimes suggested  for the following conditions, although there is no evidence whether it works or not: 

• Kidney stones 
• Urinary tract infections 
• Brittle nails 
• Minor wounds and burns (applied topically -- you should never apply herbal supplements to open wounds). 

Available Forms: 

Horsetail  is available in the following forms: 

• Dried herb 
• Liquid preparations 

Horsetail preparations should be stored in well-sealed containers to ensure protection from light. 

How to Take It:

Pediatric 

Because horsetail contains traces of nicotine, it is not recommended for young children. 

Adult

• Standardized dose: 300 mg, 3 times daily, standardized to contain 10 - 15 % silica 
• Herbal infusion (tea): 2 - 3 teaspoonfuls, 3 times daily. Pour hot water onto herb  and steep for 5 - 10 minutes. Drink as directed. 
• Tincture (1:5): 1 - 4 mL, 3 times daily 
• External (compresses): 10 g  of herb per 1 liter water daily 

Be sure to drink enough fluids when taking horsetail preparations  by mouth. 

Precautions: 

The use of  herbs is a time-honored approach to strengthening the body  and treating disease. Herbs, however, contain components that can trigger side effects  and interact with other herbs, supplements, or medications. For these reasons, herbs should  be taken  with care, under  the supervision of  a qualified health care  provider trained in the field of botanical medicine. 

Horsetail remedies prepared from Equisetum arvense  are generally considered safe. Another species of horsetail, however, called Equisetum palustre is poisonous to horses. To be safe, never take  that form of horsetail. Be sure  to buy products made by an established company with a good reputation. When possible, select products with guaranteed potency  or standardized extracts. 

Prolonged use  of even the safe form  of horsetail (E. arvense)  is also not advised. 

Taking horsetail  by mouth may cause levels  of vitamin B1 (thiamin)  in the body  to drop. If you take horsetail on a regular basis, you should also take a quality multivitamin or at least a B complex supplement daily. 

People with heart or kidney disorders, diabetes, or gout should not use horsetail. 

Do  not drink alcohol regularly while taking horsetail, because horsetail may cause levels of thiamin  to drop. 

Women who are pregnant or breastfeeding should not take horsetail. 

Possible Interactions: 

The effects of horsetail may enhance  the effects of certain medications. For this reason, people taking prescription medications should not take  horsetail without first consulting a health care provider. 

Alcohol --  People who are chronic drinkers may have low levels  of vitamin B1 (thiamin). Because horsetail can also cause low levels  of thiamin, you  should not take horsetail if  you drink heavily. 

Nicotine patches  or gum -- Horsetail contains some nicotine, and should not be used  if you are also using nicotine replacement patches or chewing gum. 

Digoxin (Lanoxin) --  Horsetail may cause low levels of potassium (hypokalemia) in the body.  People with heart arrhythmias and those taking digoxin should not use horsetail. 

Diuretics (water pills) --  Horsetail may have weak diuretic properties, meaning it helps rid the body of excess fluid. People who take diuretics  should not take  horsetail due  to the risk of dehydration or low potassium (hypokalemia). 

Notes: Dr. Nelson Crumfield

[Watch page ]

EditText of this page (last edited June 25, 2010)