Petition calls for FDA to regulate energy drinks

"You can pick up a can and drink it and get 50 milligrams, which is the amount in a Mountain Dew, or pick one up and get 500 milligrams, and that's enough to put someone who hasn't built up a tolerance to caffeine into caffeine intoxication, resulting in nervousness, anxiety, restlessness, insomnia, nausea, vomiting, tremors and rapid heart rate," Griffiths says.