The Power of Horsetail

Horsetail: The Herb that Supports Skin, Nail, Hair & Joint Health

Horsetail - Dr. Axe

When you hear the term horsetail, you probably envision the backside of an equine, but did you know there is a powerful natural herb of the same name? It’s true, and it’s one of the hidden natural treasures for health.

In fact, research shows the vast array of beneficial components horsetail holds, including: (1)

  • Vitamin C
  • Thiamine (vitamin B1)
  • Riboflavin (vitamin B2)
  • Niacin (vitamin B3)
  • Pantothenic acid (vitamin B5)
  • Pyridoxine (vitamin B6)
  • Folate
  • Vitamin E
  • Vitamin K
  • Potassium
  • Sodium
  • Calcium
  • Magnesium
  • Iron
  • Zinc
  • Copper
  • Phenolic compounds
  • Silica
  • Kynurenic acid
  • Styrylpyrones
  • Chlorophyll

What a list, right? With all that, it’s no wonder that horsetail is used for such a large variety of health problems, including urinary tract infections, edema, joint diseases, hair loss, brittle nails, skin health, diabetes, osteoporosis and more! (2, 3)

What Is Horsetail?

Horsetail is a perennial plant belonging to the genus Equisetum. There are at least 15 different species of Equisetum around the world, and “horsetail” is often used to describe the entire group. In general, the above-ground parts of the horsetail plant are used to make medicine. The common horsetail plant (Equisetum arvense) is the variety most often used medicinally.

This herb can be found growing in moist, rich soil throughout the temperate climate zones of the Northern Hemisphere, including Asia, North America and Europe. The reeds often grow wild near wetlands and other low-lying areas throughout the world. Horsetail grass or horsetail reed (Equisetum hyemale) is often used as an ornamental plant in gardens or in contained ponds.

These plants have two distinctive types of stems. The first stem grows in early spring and looks similar to asparagus, but it’s brown rather than green and has spore-containing cones on top. The mature horsetail herb comes out in the summer with branched, thin, green stems that look like a feathery tail.

Is the horsetail plant invasive? The horsetail grass plant and all varieties of this herb are known for spreading quickly and being very invasive. (3)

Health Benefits

  1. Helps Improve Brittle Nails
  2. Aids Hair Growth
  3. Heals Wounds & Relieves Burns
  4. Treats Edema
  5. Improves Joint Diseases
  6. Contains Natural Antimicrobial Properties

1. Helps Improve Brittle Nails

One of horsetail’s most well-known uses is its employment for brittle nails — topically, internally or both. Numerous anecdotal reports tell of this herb’s ability to help improve brittle nails. This is due to its high content of silicic acid and silicates, which provide about two percent to three percent elemental silicon, a nutrient known for boosting skin, hair and nail health. (4)

Scientific research confirms that Equisetum arvense is definitely rich in organic silica, including a report published in the Journal of Plastic Dermatology that encompassed two clinical trials. One clinical trail combined horsetail with a sulfur donor in a water-alcohol solution and applied it nightly for 28 days to the nails of 36 women with nail plate alterations.

What happened? The researchers observed a significant decrease in longitudinal grooves as well as an 85 percent reduction in patients reporting lamellar splitting of treated nails. Meanwhile, the untreated controls experienced no significant change in nail health.

In another study, 22 women with nail plate alterations applied the test product containing horsetail randomly on the nails of one hand only, on alternating days, for 14 days. Overall, the test product significantly improved splitting, fragility and longitudinal grooves. (5)

2. Aids Hair Growth 

Is horsetail good for hair growth? If you search the internet, you’ll see that taking horsetail for hair health is definitely a thing. As I just mentioned, it is a rich source of an organic form of silica, a mineral that has been linked with hair growth as well as healthier skin and nails.

In a double-blind, placebo-controlled study published in the Journal of Clinical and Aesthetic Dermatology in 2012, daily administration of a proprietary nutritional supplement containing silica derived from horsetail significantly increased hair growth after 90 and 180 days. The subjects of the study were women between the ages of 21 to 75 years old with self-perceived thinning hair. (6) Further research published by the Brazilian Society of Dermatology also suggests that hair strands with higher silicon content tend to have a lower fall-out rate as well as greater brightness. (7)

According to some beauty experts, horsetail is one of the best sources of silica on Earth, and it provides our hair with luster and our skin with softness. You can take a horsetail tincture or horsetail tea internally for hair health. You can also use a strongly brewed batch of horsetail tea as a DIY hair rinse. (8)

3. Heals Wounds and Relieves Burns

Is horsetail good for your skin? It contains silica, which is a mix of silicon and oxygen. Silicon is believed to be key to optimal synthesis of collagen, a key skin building block that is essential to strength and elasticity.

Multiple studies have shown that horsetail is beneficial to wound healing. A randomized, placebo-controlled trial published in 2015 in the Iranian Red Crescent Medical Journal found that a 3 percent horsetail ointment promoted wound healing and relieved pain during the 10-day time period following an episiotomy. (9) Another study out of Turkey using animal subjects published in 2013 found that ointments containing 5 percent to 10 percent horsetail provided a significant boost to diabetic wound healing. (10)

To treat burns and wounds, horsetail herb is often applied directly to the affected area of skin. (11)

Horsetail - Dr. Axe

4. Treats Edema

Horsetail is a natural diuretic that has also been shown to improve peripheral edema. A randomized, double-blind clinical trial published in 2014 in the journal Evidence-Based Complementary and Alternative Medicine had volunteers alternately take a standardized dried extract of Equisetum arvense at a dose of 900 milligrams per day, a placebo of cornstarch at the same dose or hydrochlorothiazide (a conventional edema treatment) at a dose of 25 milligrams per day for four consecutive days, separated by a 10-day washout period.

The researchers measured the diuretic effect of the horsetail supplement by monitoring the volunteers’ water balance over a 24-hour period. They found that the horsetail pills produced a diuretic effect equal to that of the conventional diuretic medicine hydrochlorothiazide without any significant changes to liver or kidney function, or to electrolyte elimination. (12) This is a noteworthy finding since many conventional diuretics are known for causing electrolyte imbalances. (13)

5. Improves Joint Diseases 

Known to hold anti-inflammatory properties and with a long history of use for calming inflammation, it’s no wonder that studies show that this herb can help with inflammatory and degenerative joint disease, as research out of the Center for Complementary Medicine, Department of Environmental Health Sciences at the University of Freiburg’s Medical Center in Germany confirms. (14)

A scientific study out of Poland published in 2013 in the Annals of Agricultural and Environmental Medicine finds that horsetail herb is one of several herbs that contain kynurenic acid (KYNA), which is known to have anti-inflammatory, antioxidative and pain-relieving abilities. Out of the nine herbs studies, horsetail was actually put into a group of four herbs (along with peppermint, nettle and birch leaf) that possessed the highest KYNA content.

Previous research had shown that the amount of KYNA in the synovial fluid of patients with rheumatoid arthritis is lower than in patients with osteoarthritis. Overall, the researchers conclude that “the use of herbal preparations containing a high level of KYNA can be considered as a supplementary measure in rheumatoid arthritis therapy, as well as in rheumatic diseases prevention.” (15)

Using an an in vivo model of acute inflammation, another study published in the Open Rheumatology Journal looked at the effects of a horsetail extract as a form of immunomodulatory therapy on antigen-induced arthritis in mice subjects.

The researchers found that the extract showed “anti-inflammatory potential” along with an immunomodulatory effect on both B and T lymphocytes. (16) These lymphocytes are also called B-cells (bone marrow cells) and T-cells (thymus cells), and they are considered to be the “special ops of the immune system,” making this a very significant research finding for autoimmune arthritis like rheumatoid arthritis. (17)

In vitro and animals research has even shown that horsetail may help boost bone regeneration and reverse bone changes resulting from osteoporosis. In fact, one study out of Portugal concluded that “results showed that E. arvense extracts elicited inductive effects on human osteoblasts while inhibiting activity of S. aureus, suggesting a potentially interesting profile regarding bone regeneration strategies.” (1819)

6. Contains Natural Antimicrobial Properties

An antimicrobial is a substance that kills or stops the growth of microbes, such as bacteria, viruses, fungi and parasites. Research shows that Equisetum arvense essential oil is a super impressive antimicrobial agent.

In fact, a study published in the journal Phytotherapy Research out of the University of Nis in Serbia and Montenegro tested the oil against a wide variety of harmful, disease-causing bacteria and fungi, including Staphylococcus aureusEscherichia coli, Klebsiella pneumoniaePseudomonas aeruginosa, Salmonella enteritidisAspergillus niger and Candida albicans. A 1:10 dilution of the Equisetum arvense essential oil “was shown to possess a broad spectrum of a very strong antimicrobial activity against all tested strains.” (20)

How to Use

You can find horsetail in many forms — including dried herb, tea, capsule, tincture and juice — either at your local health store or online. There are also creams, lotions and ointments, along with numerous hair and nail products, for topical use.

You can make a cup of tea by using horsetail teabags, or you can make it using the loose herb.

How to make horsetail tea:

  1. Pour one cup of boiled water over 2–3 teaspoons of fresh or dried herb.
  2. Allow it steep for 5–10 minutes.
  3. Strain the tea, and add raw honey or stevia if desired.

The appropriate horsetail dosage depends on several things, including a person’s age and health status. There is currently not enough scientific information to indicate an appropriate standard dose or range of doses. Many supplements contain 300 milligrams of dried extract per capsule and can typically be taken up to three times per day. Always read product labels carefully for dosing information, and consult a professional if needed.


Equisetum is derived from the Latin equus (“horse”) + seta (“bristle”). The horsetail plant is believed to be a descendant of huge trees that lived during the Palaeozoic Era (600–375 million years ago). The plant doesn’t have any leaves or flowers and grows in two stages.

Native Americans liked to use it to naturally treat kidney and bladder problems. Tribes like the Potowatami and Colville-Okanagan created an infusion of the plant for use as a natural diuretic to improve kidney function. Meanwhile, the Chippewa created a decoction from horsetail stems to treat painful or difficult urination. (21)

Concentrated liquid forms of this herb are also added to a bath water for sprains and fractures or to boost hair and/or skin health.

Risks, Side Effects and Interactions

Is horsetail poisonous to humans? Marsh horsetail (Equisetum palustre) is known to be poisonous. If you gather the fresh plant for medicinal use, it’s important to know exactly what variety you’re handling. In addition, plants with brown spots should be completely avoided since these spots may indicate the presence of a toxic fungus.

Mild side effects of the horsetail herb include upset stomach, diarrhea and increased urination. Possible severe side effects that may indicate kidney damage and warrant medical attention include kidney pain, lower back pain, pain while urinating, nausea and/or vomiting. Taking too much can result in heart palpitations. Seek immediate medical attention if you experience heart palpitations after taking horsetail herb in any form.

Horsetail is considered to be possibly unsafe when taken for long periods of time by mouth. It naturally contains a chemical called thiaminase, which breaks down the vitamin thiamine, so there is concern that over-supplementation with this herb could make a thiamine deficiency worse. This is why some horsetail products are labeled as “thiaminase-free.” Since alcoholics tend to also be deficient in thiamine, horsetail is typically not recommended for people with alcoholism.

Speak with your doctor before using this herb if you are taking medication or have any ongoing health concerns, especially if you are pregnant, breastfeeding, have diabetes or have low potassium levels. Horsetail may lower blood sugar and potassium levels.

Moderate medication reactions are known to possibly occur with antidiabetes drugs, lithium and diuretics (water pills). Horsetail may interact with the following herbs and supplements: areca, thiamine, herbs and supplements that may lower blood sugar, and chromium-containing herbs and supplements.

Final Thoughts

  • Horsetail comes in many varieties, but the one most often used medicinally is Equisetum arvense.
  • The herb contains a wide variety of vitamins, minerals and beneficial plant compounds.
  • Horsetail benefits include boosting the state of hair, skin and nails; improving joint and bone health; acting as a potent antimicrobial against harmful bacteria, including those that cause staph infections and candida; wound healing; burn relief; and treating edema.
  • Speak with your doctor before using horsetail if you are taking medication or have any ongoing health concerns, especially if you are pregnant, breastfeeding, have diabetes or have low potassium levels.

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