But labels don't have to reveal how much caffeine ... practices of energy-drink companies, said a person familiar with the inquiry. Living Essentials (maker of 5-hour Energy), Monster Beverage ...

For those that require an infusion of energy that coffee can't provide, there are a number of energy drinks to choose from.

Are you curious about how millions of Monster Energy cans are produced each day? Step into the cutting-edge world of Monster ...