Horsetail, or Equisetum arvense, is an herb that has historically been used as a diuretic to make you urinate more frequently. Diuretics affect the kidneys, increasing the amount of water and salt that are released into the urine. For people with kidney problems or edema (when the body holds onto fluid), getting rid of unwanted fluid and salt can be an important part of treatment.
Horsetail is a descendant of a much larger plant that grew three hundred million years ago. Today, it grows in Europe, North America, and Canada. Its tube-like stems and scale-like leaves make it looks like a cross between a bamboo plant and a fern. The leaves and stems are either made into a liquid extract or dried for purchase in tea or capsule form.
How It Works
Horsetail is believed to contain chemicals that increase the amount of urine the body produces. While diuretic medications aren’t a mystery, scientists aren’t yet sure exactly how or why the herb works. There is also very little evidence to prove that the ancient remedy is effective. A recent study compared horsetail to a common diuretic, hydrochlorothiazide, and found the herb to be as effective as the medication. However, the study was very small.
Horsetail has been used medicinally since as far back as ancient Greece. Along with helping you urinate, it’s also used for skin and nail care, wound healing, osteoporosis, and bone repair. Experts believe these potential health benefits are due to a mineral called silica, which helps the body store the calcium it needs to heal bones and build strong fingernails and hair.
In addition to being helpful to bone health, silica gives horsetail a coarse texture that makes it useful for cleaning. For this reason, the herb is used in some beauty products such as facial cleansers and shampoos.
Where to Get It
You can buy horsetail supplements in pill form or as a tea at most health food stores. The tea is made by boiling a teaspoon of dried horsetail with water and adding sugar. If you live in an area where horsetail grows, it’s also possible to cut the herb and dry it yourself.
Since there have been few studies on horsetail, there are no standardized doses yet. Supplements generally have recommended doses on the labels. Check with your doctor or pharmacist before you start using it.
Like most herbal supplements, horsetail is not approved by the U.S. Food and Drug Administration (FDA). As a diuretic herb, it might cause the body to flush out essential nutrients, such as potassium. It also has an enzyme that destroys thiamine, vitamin B1, and may lead to thiamine deficiency if taken long term. It can also affect the way your body processes lithium, which could cause dangerous side effects if you use it as medication. People with diabetes should be cautious when it comes to horsetail, as it can drastically lower blood sugar.