Tarragon is a spice herb with a long history of culinary and medical use. There exist two cultivars of this species: French Tarragon is used as a spice in cuisine and Russian Tarragon (RT) has been used medically in Russia and middle Asia, mainly to treat gastrointestinal disorders. However, recent studies also reported possible antidiabetic and hypoglycemic activities. Ribnickyet al. demonstrated that an ethanolic extract of RT was able to reduce blood glucose concentration in rodents. Tarragon like many other spices contains potential harmful essential oil constituents like estragole and methyleugenol. Thus, it was officially advised to limit the intake of such herbal spices. Therefore, as a solution to this problem, an aqueous extract of RT (RTE), which does not contain these compounds, was developed (Finzelberg GmbH & Co.KG, Germany) for further investigation. In vivo animal and human study demonstrate promising potential of the aqueous extract as a new potent antidiabetic agent.