A new warning tonight about teenagers and those energy drinks.
There can be some dangerous side effects.
Teens are driving the $5 billion a year market with 35% of them drinking them on a regular basis.
A new study says high doses of caffeine in them can cause heart palpitations, anxiety, insomnia, elevated blood pressure, and digestive problems.
Plus, they're not the healthiest drinks.
They contain high amounts of sugar.