Twenty year old Kylie Berck said she used to drink a lot of Monster Energy drinks in high school, until she realized what she was drinking might not be safe.
"I've had a couple of friends, or at least heard about people having a heart attack after drinking one of them, and I just didn't want to risk it anymore," Berck said.
Those risks were magnified for Berck this week, when the Food and Drug Administration released several reports on illnesses and deaths related to energy drinks. In particular, Red Bull, 5-Hour Energy, Rockstar, and Monster -- the brands cited for possible involvement in 18 fatalities and more than 150 injuries since January 2004.
The reports don't surprise substance abuse professionals, who say energy drinks can be dangerous.
"It causes heart palpitations, increased blood pressure, anxiety, nausea. It's all the speedy effects any other speed derivative drug would give," said Sue Hieb, an alcohol and drug counselor at the St. Francis Alcohol and Drug Treatment Center.
Other symptoms listed in the FDA's reports include dizziness, chest pain, disorientation, and convulsions. Experts said it's not just the caffeine, but how fast people drink them that can cause problems.
"Coffee would be another thing, but I don't think they drink it as fast. If you're going to drink five cups of coffee, you're going to drink it throughout the morning, whereas with the energy drinks you drink them in five minutes," Hieb said.
And sometimes it's more than just one serving. 20-year-old Brandon Lambert, for example, admits to frequently drinking three to four Red Bulls in an hour.
"Not so much that it gives me energy. I just like the taste," Lambert said.
The FDA linked many of the deaths to young adults, leading numerous legislators across the country to consider tighter regulations for those under 21.
The FDA notes that the reports do not mean an energy drink caused an illness or death, just that it may be linked. Representatives for all four brands have said that their products are safe.