You will receive a sense of fullness when you take these pills as directed. They also give you an alert feeling, however, they didn't make my heart race. These pills are also a great source of vitamins as well. I watched what I ate while taking these and also exercised. I began taking these at the start of a new diet and they aided in kick-starting it. I would reccommend these as a supplement to a great workout regime and a healthy way of eating.