Horsetail is very rich in silicic acid and silicates, which provide approximately 2-3% elemental silicon. Potassium, aluminum, and manganese along with fifteen different types of bioflavonoids are also found in the herb. The presence of these bioflavonoids are believed to cause the diuretic action, while the silicon content is said to exert a connective tissue-strengthening and anti-arthritic action.
