The best kind of stevia to get is the 100% stevia powder. The little supplement bottles that are all over the shelves called stevia are full of filler and don't last very long at all. I found some doing a Google search. It takes some searching, but it's worth it! Looks expensive, but when it's 100% pure stevia powder it lasts a really long time and is worth the investment (and actually saves money compared to buying the stuff full of fillers)!