Unlike other zero-calorie sweeteners—sucralose, aspartame, saccharin—stevia is not artificial. It’s a plant named stevia rebaudiana (sometimes known as candy leaf or sweet leaf) thus making it a natural sweetener. Stevia leaves are about 200 to 300 times sweeter than sugar, which means you need very little to sweeten a food or drink.

The stevia used in food products is actually stevia leaf extract, explains Lisa Lefferts, M.S.P.H, senior scientist for the Center for Science in the Public Interest (CSPI).