Horsetail is a perennial fern that belongs to the genus Equisetaceae. It has been used as a herbal remedy since the times of the Greek and Roman Empires.
The chemicals in horsetail have antioxidant and anti-inflammatory effects and is used for fluid retention, urinary tract infections, loss of bladder control, wounds, and to improve skin, hair, and bone health.
Horsetail is mostly consumed in the form of tea, which is made by steeping the dried herb in hot water, though it is also available in capsule and tincture form and is sometimes used in cosmetics and shampoos.