NRI's energy drink under scanner for 13 deaths in US

The drink is a "compact sized energy shot intended for busy adults," she said adding that "5 hour Energy is marketed to hardworking adults who need an extra boost of energy.

"The dietary supplement has no sugar, contains only four calories and no herbal stimulants...It contains about as much caffeine as a cup of the leading premium coffee.

"When consumed according to our recommended use guidelines, 5-hour Energy is an effective dietary supplement, although individual results may vary," she said.

Lutz stressed that any complaint filed against the drink with the USFDA does not mean that the dietary supplement was "involved, caused or contributed to the adverse event being reported."

In August, the New York attorney general began an investigation into 5-Hour energy and its rivals Monster and Amp to look into whether the products' labels match their actual contents.

Last month, the FDA had received reports of five deaths, which were attributed to Monster, which is another popular energy drink.