DETROIT -

The U.S. Food and Drug Administration is investigating the possible link of 5-Hour Energy shots to as many as 13 deaths.

The FDA confirms it is also investigating dozens of adverse events reported to the agency over a span of four years. These include heart attacks and convulsions, among others, and one case of spontaneous abortion.

Local 4 Consumer Expert Ruth Spencer hit the pavement to find people who use 5-Hour Energy. It didn't take long for her to find those who've taken the supplement to get a boost.

Rebecca Rahim says she frequently consumes of the high-caffeine drink. "I actually get it all the time, so does my boyfriend. He's addicted to it." she said.

"I've seen a lot of kids around school drink them," said Derrick Rassam, of West Bloomfield.

Laura Lemley works in a gas station that sells 5-Hour Energy. She says it works for her, but one time she took a lot of them, and felt her heart racing. She says she was scared when it happened.

"Then I slowed way down on them," she said.

What does 5-Hour Energy say?

Living Essentials, the company that makes 5-Hour Energy, is based in Farmington Hills.

Local 4 Consumer Expert Ruth Spencer went to the corporate offices, hoping to speak with CEO Manoj Bhargava. She was told he's in New York and couldn't speak until Friday.

Read: 5-Hour Energy's complete statement

The company released a statement that made several points including the following:

*There's no proven link between its products and any deaths.
*Product labels and website warn customers not to exceed two bottles per day.
*Consumers with a caffeine sensitivity should consult with a doctor and consider the "decaf" version.

5-Hour Energy at store