Horsetail

What does horsetail do?

Horsetail works mainly through its high content of silica and other plant compounds.

Silica supports the structure of connective tissue, such as skin, hair, nails, bones, and joints. This explains the traditional medicinal use of horsetail.

Horsetail also has a mild diuretic effect. It increases urine production, which supports the natural removal of excess fluids.

In addition, horsetail contains antioxidants that help protect cells against oxidative stress.

What are the side effects of horsetail?

Horsetail is generally well tolerated when used for short periods, but side effects can occur.

Horsetail is not toxic when the correct (edible) species is used and it is taken in normal amounts.

The most common side effect is increased urination. This may lead to fluid or electrolyte loss when used in high amounts or for a long time.

Horsetail contains small amounts of thiaminase. Long-term use may reduce vitamin B1 levels if intake is not sufficient.

In sensitive people, horsetail may cause stomach discomfort, such as nausea or mild stomach pain.

Horsetail is not recommended during pregnancy or breastfeeding due to limited safety data.

Horsetail extract or tea?

Horsetail extract and horsetail tea mainly differ in concentration and ease of use. Horsetail extract is usually stronger and more standardized, so a small dose provides a consistent amount of active compounds. This makes it suitable for targeted and longer-term use.

Horsetail tea is milder and less concentrated. Its strength depends on brewing time and herb quality. People often choose tea for the ritual of preparation and because it is easy to drink as a warm beverage. The most suitable form depends on the intended effect and personal preference.

Written by Wouter Olthof
Reviewed by Liesbeth Thoen

Updated on January 9, 2026