Stevia () is a sweetener and sugar substitute extracted from the leaves of the plant species Stevia rebaudiana, native to Brazil and Paraguay. The active compounds are steviol glycosides (mainly stevioside and rebaudioside), which have 30 to 150 times the sweetness of sugar, are heat-stable, pH-stable, and not fermentable. The body does not metabolize the glycosides in stevia and therefore it contains 0 calories like some artificial sweeteners. Stevia's taste has a slower onset and longer duration than that of sugar, and some of its extracts may have a bitter or licorice-like aftertaste at high concentrations.
The legal status of stevia as a food additive or dietary supplement varies from country to country. In the United States, high-purity stevia glycoside extracts are generally recognized as safe (GRAS) since 2008 and allowed as ingredients in food products, but stevia leaf and crude extracts do not have GRAS or Food and Drug Administration (FDA) approval for use in food. The European Union approved stevia additives in 2011, while the people of Japan have widely used stevia as a sweetener for decades.