This case study involves the biochemical analysis of the components of commonly available energy drinks, which many students purchase at fairly high prices. Students research the ingredients in each product and their physiological role in the human body, and then attempt to match what they learn with the product manufacturers' marketing claims. The case can be used as a review of basic biochemistry and nutrition for upper level students in physiology, biochemistry, or nutrition courses--or to introduce this information in basic courses in these disciplines.