Horsetail Tea (Cola de Caballo): Benefits for Hair, How to Make It & Side Effects
Tea guide · Yado Market Blog
Horsetail tea, known in Spanish as cola de caballo, is brewed from the dried stems of Equisetum arvense, one of nature's richest plant sources of silica. It is a traditional tea for flushing the body of extra water and a favorite in hair, nail and skin routines. Here are the real benefits, what research says, how to make it and who should check with a doctor first.
Quick answer: what is horsetail tea good for?
- A traditional natural diuretic to flush the urinary tract.
- Naturally rich in silica, popular for hair, nails and skin.
- Brew 1 to 2 tsp in hot water for 5 to 15 minutes.
- Best used short-term; choose thiaminase-free products.
E. arvense
Scientific name
5–8%
Silica in the stems
0 mg
Caffeine
2–4 weeks
Traditional course
Know your herb
What Is Horsetail Tea?
Horsetail tea is made from the dried green stems of field horsetail, Equisetum arvense, a fern-like plant with no flowers that grows in low, wet places across North America, Europe, the Middle East and Asia.1 Its jointed, brush-like stems gave it old English names like shave grass, scouring rush and bottle brush.2
In Spanish it is called cola de caballo, literally "horse's tail."3 In Brazil it is called cavalinha.4 Horsetail is famous for one thing above all: its stems are naturally rich in silica.
English
Horsetail, field horsetail, shave grass.
Spanish
Cola de caballo.
Portuguese (Brazil)
Cavalinha.
Botanical
Equisetum arvense L.
At a glance
Horsetail Tea Quick Facts
| Scientific name | Equisetum arvense L. (field horsetail) |
|---|---|
| Other names | Cola de caballo, cavalinha, shave grass, scouring rush, bottle brush |
| Part used | Dried green (sterile) stems, cut for tea |
| Key natural compounds | Silica and silicic acid (about 5% to 8% of the stems), plus flavonoids and caffeic acid esters21 |
| Traditional uses | Flushing the urinary tract, water retention, and support for hair, nails and skin15 |
| Taste | Mild, grassy and slightly mineral, lighter than green tea |
| Caffeine | None (it is an herbal tea) |
Hair, nails & skin
Horsetail for Hair, Nails and Skin: The Silica Story
Horsetail is one of the richest plant sources of silica, with stems containing about 5% to 8% silica and silicic acids.2 Silicon is a trace mineral found in hair, nails, skin and connective tissue, and that is why horsetail has long been a favorite in beauty routines and in "hair, skin and nails" formulas. Today you will see horsetail extract in shampoos, conditioners and supplements.
Nails
Two clinical trials of a nail product that combined horsetail with other ingredients reported less splitting and breaking.2
Hair
Many people drink horsetail tea or rinse with it as part of a hair routine. Human studies on horsetail tea alone for hair growth are still lacking.
Skin
In Europe, horsetail is a traditional herbal remedy applied to the skin to support healing of small, superficial wounds.5
The honest take: horsetail is a natural, mineral-rich herb that fits nicely into a hair and nail care routine, but researchers have not yet proven that the tea by itself grows hair. Enjoy it as part of the bigger picture: good food, protein, and gentle hair care.
What scientists found
Horsetail Tea Benefits: What Research Says
The best-studied benefit of horsetail is its traditional use as a natural diuretic, meaning it helps the body pass more water.
- A randomized, double-blind human trial. In a 2014 study from Brazil, 36 healthy men took a standardized dried horsetail extract (900 mg a day), a placebo, or the prescription diuretic hydrochlorothiazide (25 mg) for 4 days. Horsetail had a stronger diuretic effect than placebo and an effect comparable to hydrochlorothiazide, without significant loss of electrolytes, and only rare minor side effects.6
- Recognized in Europe. The European Medicines Agency lists horsetail as a traditional herbal medicine to increase urine and flush the urinary tract as a support for minor urinary complaints.5
- Lab studies. Laboratory research suggests antioxidant, anti-inflammatory and liver-protective activity, and animal studies show diuretic effects.1
That trial was small and short and used a measured extract rather than home-brewed tea, so think of horsetail tea as a gentle, traditional support, not a replacement for medicine your doctor prescribes.
Step by step
How to Make Horsetail Tea
The European herbal monograph gives a simple traditional recipe: 1 to 4 grams of dried herb (about 1 to 2 teaspoons) per cup of boiling water, up to 3 to 4 cups a day.5 Follow your package directions if they differ.
1. Measure
Add 1 to 2 teaspoons of dried horsetail to a mug or teapot.
2. Pour
Cover with about 150 ml (5 oz) of freshly boiled water.
3. Steep
Cover and steep 5 to 15 minutes. Longer gives a stronger, more mineral cup.
4. Strain & sip
Strain and drink warm. Add honey, lemon or mint if you like.
Traditional use is for 2 to 4 weeks at a time, then take a break.5 Because it makes you pass more water, drink plenty of plain water through the day too.
Good to know
Taste, Blends and Tips
What it tastes like
Mild, green and grassy with a light mineral finish. Easy to drink plain.
Blend it
Try it with a pinch of mullein (gordolobo), or simply add mint and lemon.
Hair rinse
Some people cool a strong cup and use it as a final hair rinse after washing.
Storage
Keep the dried herb in a sealed bag or jar, away from heat, light and moisture.
Shop smart
Horsetail Tea Side Effects: Who Should Check With a Doctor
Horsetail is generally well tolerated in short-term use; the most common complaints are mild stomach upset or loose stools.1 A few smart rules make it even safer:
- Use it short-term. Long-term daily use by mouth is not recommended.3
- Thiamine (vitamin B1). Crude horsetail contains thiaminase, an enzyme that breaks down thiamine. Canada does not allow thiaminase in horsetail supplements unless its removal is documented, so look for products labeled thiaminase-free when you can, and take extra care if you drink alcohol heavily or have low thiamine.32
- Lithium and water pills. Because it is a diuretic, horsetail may slow how the body clears lithium and, in large amounts, lower potassium, especially with prescription diuretics.3
- Pregnancy and breastfeeding. Safety has not been established, so it is best avoided.53
- Kidney or heart disease. If your doctor has asked you to limit fluids, or you have kidney disease, do not use horsetail without medical advice.5
Not recommended for children under 12.5 If you have diabetes, note that horsetail may lower blood sugar.3
Shop horsetail
Buy Horsetail Tea (Cola de Caballo)
Our organic horsetail tea is ready to brew. Pair it with other favorite herbal teas from the same shelf:
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Organic Horsetail Tea
Premium dried horsetail for daily cups and hair rinses.
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Frequently Asked Questions
What is horsetail tea good for?
Horsetail tea is traditionally used as a gentle diuretic to help flush the urinary tract and reduce water retention. It is also popular for hair, nail and skin care because the plant is naturally rich in silica.
Is horsetail good for hair growth?
Horsetail is rich in silica, a mineral found in hair, and it is a popular ingredient in hair products and routines. Small studies support horsetail-based products for nails, but human studies on horsetail tea alone for hair growth are still lacking.
What is cola de caballo tea?
Cola de caballo is the Spanish name for horsetail (Equisetum arvense). Cola de caballo tea is the same herbal tea made from its dried stems.
How do you make horsetail tea?
Steep 1 to 2 teaspoons (1 to 4 grams) of dried horsetail in about 150 ml of boiling water for 5 to 15 minutes, then strain. Up to 3 to 4 cups a day is the traditional amount.
What are the side effects of horsetail tea?
Most people tolerate it well short-term; mild stomach upset can happen. It contains thiaminase, which can lower vitamin B1, so use it short-term and choose thiaminase-free products. Avoid it in pregnancy, with lithium or water pills, or with kidney disease unless your doctor says it is fine.
Where can I buy horsetail tea?
At Yado Market: pick up at 1651 E 87th St in Chicago, local delivery, or shipping anywhere in the U.S.
Keep reading
Related Guides
Brew Your First Cup of Cola de Caballo
Organic horsetail tea, ready to ship anywhere in the U.S. from our Chicago store.
This guide shares traditional uses and published research for general information. It is not medical advice, and these statements have not been evaluated by the FDA. If you are pregnant, nursing, take prescription medicine or have a health condition, check with your doctor before using herbal products.
Research & references
Sources
- Horsetail, LiverTox: Clinical and Research Information on Drug-Induced Liver Injury, NIDDK / NCBI Bookshelf (updated 2022)
- Horsetail monograph, Drugs.com Natural Products (Wolters Kluwer)
- Horsetail: uses, side effects and interactions (Therapeutic Research Center data), RxList
- Avaliação da atividade diurética e segurança do uso da Equisetum arvense L. (Cavalinha) em humanos saudáveis, Universidade Federal de Goiás
- European Union herbal monograph on Equisetum arvense L., herba, European Medicines Agency (EMA/HMPC/278091/2015)
- Carneiro et al., Randomized, Double-Blind Clinical Trial to Assess the Acute Diuretic Effect of Equisetum arvense (Field Horsetail) in Healthy Volunteers, Evidence-Based Complementary and Alternative Medicine (2014)