I have been using stevia for 11 years, and have had no negative effects. I use it to bake sweet type desserts with, and in my tea, lemonade, etc. It is, according to my research, 20 times sweeter than sugar. The brand I use comes with a mini-spoon that equals a teaspoon of sugar so you can easily substitute. I use drops for cold beverages since the powder doesn't dissolve well in cold liquids. If you get too much it is almost unbearable, so I sneak up on it when trying it in something new. Beware of different brands, especially those in packets as they tend to have other ingredients that are not very good. Typically they are sugar additives, so if you are trying to avoid sugar you many be getting it without knowing. Also beware of stevia-like brands (i.e. Truvia), which have been formulated so that they can be patented and may not be as healthy as pure stevia. Stevia comes from a green leafed plant and does not contain any sugar.