The hugely popular energy drink, Prime Energy, is under scrutiny for its eye-popping caffeine levels – with health experts in the US the latest to call for the product to be banned. A 12oz (330ml) can of Prime contains 140mg of caffeine, the equivalent of nearly six cans of Coke and almost twice as much as Red Bull. Prime is already banned in British and Australian schools due to concerns about heart problems, anxiety and digestive issues in children.