Aim Energy drinks are widely consumed worldwide and are recognised for their adverse health effects, usually due to their high caffeine content. However, little is known about their impact on oral and general health. The aim of this investigation was to review the most popular energy drinks sold in the UK, for their possible effect on oral health and contribution to obesity. Materials and methods Five drinks representing 75% of the UK energy drinks market were purposively selected (Lucozade, Red Bull, Monster, Rockstar and Relentless). pH and sugar content were measured and their ingredients reviewed in the context of oral and general health, focusing on dental caries and erosion and obesity. Results All five energy drinks investigated had pH values below the critical value (5.5) associated with dental erosion; the lowest pH was 2.72 (Lucozade) and the highest was 3.37 (Monster). The drinks also contained excessive amounts of free sugars, ranging from 25.5 g (Red Bull) to 69.2 g (Rockstar). Differences in sugar content were mainly explained by portion size. Other ingredients contained within the energy drinks, caffeine and various acids, are also linked to oral and general health. Conclusion Regular consumption of energy drinks could contribute to dental erosion and the development of obesity. Lucozade and Rockstar were found to potentially have the greatest impact on oral health and obesity. Achieving a healthy product by reformulation is highly unlikely due to the very high initial free sugar content. Thus, health professionals need to acknowledge the popularity of these products and help their clients to reduce their use. This is the first study which compares in detail the potential oral and general health consequences of overuse of a selection of energy drinks popular in the UK.