Stevia extract is produced from the leaves of Stevia rebaudiana, a small shrub in the Chrysanthemum family that is native to Paraguay and Brazil. For centuries, South Americans have used the leaf to sweeten a local beverage known as yerba mate.
While the leaf is said to be provide up 15 times the sweetness of cane sugar, the extract, which contains up to 95% steviosides, can be as much as 300 times sweeter.
Although stevia leaf is widely used around the world in the manufacture of sugar-free foods, beverages and candies, the US Food and Drug Administration does not currently approve of the use of the herb as an alternative sweetener or food additive. After more than a decade of debate regarding the established safety of stevia that involved lobbyists from the artificial sweetener and natural food industries, a compromise was reached to permit the use of refined stevia as a dietary supplement.