Horsetail Equisetum arvense L. belongs to the Equisetaceaehorsetail family. In Poland, it is commonly found over the entire country, and it is also cultivated for medicinal purposes. Horsetail herb Equisetiherba is the herbal raw material which first of all contains large amounts of dissolved SiO2 silica, and additionally: flavonoids (quercetin and kaempferol glycosides), as well as other mineral components (potassium, calcium, iron, manganese and magnesium salts). Horsetail herb products are traditionally used in case of slight urinary tract disturbances, in order to increase urine production to flush it, and also in the treatment of superficial wounds. It is also common and efficient to use horsetail in order to improve the condition of skin, hair and nails.