Escin Ia and isoescin Ia have been traditionally used clinically as the chief active ingredients of escin, a major triterpene saponin isolated from horse chestnut (Aesculus hippocastanum) seeds for the treatment of chronic venous insufficiency, hemorrhoids, inflammation and edema. The interconversion of escin Ia and isoescin Ia when given alone indicates that administration of one isomer leads to exposure to the other.