PHYTO PHYTOFARMA retardhorsetail. The flavonoids and potassium salts of horsetail justify its diuretic action. The abundance of silicic salts gives it remineralizing properties and contributes to the maintenance of the fundamental substance of the connective tissue (collagen) by the fibroblasts, increasing the elasticity of the tissues. Increases the nonspecific defenses of the body. Due to the abundance of tannins, horsetail is astringent (antidiarrheal), hemostatic (due to local vasoconstriction) and healing.