I took this more for energy than anything else. It was very potent and I could only take 1 capsule per day in order to not get the jitters. I did notice a huge boost in energy throughout the day and good weight loss results. I took this product for 60 days and lost 20 pounds due to increased energy and high cardio workouts. I would plan on doing on a half hour on the treadmill and instead would find myself doing about an hour or longer before feeling tired. Started at 1 mile per day and soon increased to 7-8 miles per day before I did any weight training. Did have a little trouble sleeping at night the first few weeks. Have not taken for over a year and the weight has come back.