As with the other artemisias, Tarragon is a digestive aid and vermifuge, but Tarragon also promotes good circulation and excretion of uric acid. It is often used to reliever discomfort associated with menstruation as well as rheumatism and arthritis. Dr. Jean Valnet did extensive studies of essential oil and determined that Tarragon, often called the King of Herbs in France, has very strong antioxidant properties and is therefore effective in counteracting the action of free radicals, including those associated with malignancies and cataracts.