Energy drinks contain several ingredients with primarily stimulating effects. Consumption of these drinks greatly increased in the last several years, especially among young people. Recently, scientists focused on investigating their safety. Apart from its desirable effects like boosted mental and physical performance, studies show that energy drinks can also cause adverse effects, which currently remain not well described. The purpose of this article was to present current trends in energy drink consumption among young adults and to describe the mechanisms of adverse effects, which might be caused by it. The ingredients of energy drinks, like caffeine, consumed in high doses ( > 200 mg/day), were shown to cause shaking, dizziness, heart palpitations, and sleep disorders. The excessive consumption of energy drinks can also lead to electrolyte imbalance, and heart-related diseases, e.g. myocardial infarction. It is essential to familiarise oneself with the composition of the energy drinks and follow the recommendations for maximum daily intake of substances contained in these drinks. In addition, it is necessary to raise awareness of pharmacological mechanisms of possible side effects and to further the research on the consumption of energy drinks, especially among young people.