Horseradish contains volatile oils that are similar to those found in mustard. These include glucosinolates (mustard oil glycosides), gluconasturtiin, and sinigrin, which yield allyl isothiocynate when broken down in the stomach. In test tubes, the volatile oils in horseradish have shown antibiotic properties, which may account for its effectiveness in treating throat and upper respiratory tract infections.¹ At levels attainable in human urine after taking the volatile oil of horseradish, the oil has been shown to kill bacteria that can cause urinary tract infections² and one early trial found that horseradish extract may be a useful treatment for people with urinary tract infections.³ Further studies are still necessary, however, to confirm horseradish’s safety and effectiveness in treating urinary tract infections.