No, stevia is simply an extract from a plant that is naturally sweet and is used as a sweetener. Has no effect (presumably) on the GI system, but is recommended by many because it's a natural sugar alternative. I'm giving Stevia- Plus (kind of a brand name for this particular combination of stevia and inulin, I think) a try; just started it today so it's too early to tell. I've used just plain old stevia often in the past. Works well as a sweetener; you have to get used to a slightly different kind of sweet taste, but it's worth it to know you're not using sugar and not using a chemical sugar substitute.