With names like rock star, red bull and monster, teens are drawn to energy drinks.

"I was really curious about them," 17-year-old Orin said.

"I started drinking them because my friend was drinking them,” 15-year-old Kathy said.

Ryan, 18, said he used to down eight energy drinks a day.

"I'd come to school with like three or four, and by lunch, they'd be gone," Ryan said.

Dr. Peter Antevy said energy drinks are especially harmful to the still-growing teenage brain.

"The FDA went ahead and approved these drinks with ingredients that have never really been looked at," Antevy said.

An eight-ounce cup of coffee averages 85 ml of caffeine. One energy drink has up to 500 ml.

"Imagine the high you get and the crash that ensues quickly after that,” Antevy said.

Energy drinks also contain taurine, guarana, mega-doses of B vitamins and a potent "energy blend" -- all of which can increase heart rate. Antevy said the mixture can cause serious heart problems -- even death. Consuming too many energy drinks has also been linked to anxiety and high blood pressure.

"I think that these drinks should be banned in the U.S.” Antevy said. “They should not allow these companies to put that amount of caffeine in a drink."

Ryan kicked his habit after he clocked his resting heart rate at 117 beats per minute. A normal resting heart rate is between 60 and 100.

"I was actually very scared,” Ryan said. “I thought I was sort of like having a heart attack."

Orin, Kathy and Mike know the risks, but they still drink them.

"I'm not going to drink them for the rest of my life," 17-year-old Mike said.

The drinks may keep them energized, but teens might want to think about the dangers before they take another sip.

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