The purpose of this study is to investigate the effects of a post consumption slump after using energy drinks on memory attention and perceived mental sharpness, in a sample of forty volunteers (M=21, F= 19).The age of the participants ranged from 25 to 50. A quantitative between groups experiment was carried out. Participants were randomly assigned into two groups 1: sugar free Red Bull group 2: Placebo group. Three tests to measure memory and attention were given to the participants after 4 hours of consuming the drinks. Analysis showed the Red Bull Groups performance was poorer overall; however the results were only significant in the trial making task.