It just gives it a little jolt. Good for if you haven't smoked in a while and want to put some fuzz back into the high. Weed buzzes start going downhill after a cig or two, in my experience. Its like a short jolt then a quick downer. If you don't already smoke them, its certainly no rerason to start. I notice that, when I lay of tobacco for a week or so, I feel a lot more naturally high and hyper without taking anything to get myself that way, compared to when i spend a few weeks using it and need to use it every few minutes.