Energy drinks are beverages that contain ingredients which increase energy and mental performance. Nearly all energy drinks contain the ingredient caffeine which stimulates brain function and increases alertness and concentration. They may or may not be carbonated and may also contain sugar, other sweeteners, herbal extracts, taurine and amino acids. They are aslo full of unhealthy and even dangerous ingredients like caffeine, guarana and others. Energy drinks can lead to lots of health issues like caffeine overdose which can be life-threatening. The adverts for energy drinks usually feature increased muscle strength and endurance but there is still no scientific consensus to support these claims. RedBull, 5-Hour Energy, Monster, AMP, Rockstar, NOS and Full Throttle are examples of popular energy drink products. They are illigal in a lot of countries.