Energy drinks are beverages that contain caffeine. They are particularly marketed to improve performance and stamina.
Despite their name, energy drinks do not contain any more energy, i.e. sugar, than any other soft drinks, but they are assumed to be sources of "energy" due to the compounds of stimulants that they contain, such as caffeine, guarana, taurine or glucuronolactone. Energy drinks are often also fortified with varying levels of group B vitamins, inositol and choline.