The federal government is investigating claims that 13 people have died after drinking 5-Hour Energy in the past four years.
Another 33 hospitalizations linked to the popular energy shot have been reported in that same time period, according to the Food and Drug Administration.
"If someone is to use multiple cans, now is when we start to see some of the side effects," Dr. Sean Patrick Nord, USC Director of the Section of Toxicology, told ABC News. "You're getting astronomical amounts, 30 to 40 cups of coffee."
In a statement, FDA officials said they will take action if the deaths can be directly linked to the drink.
Such action could include forcing the company to take the drinks off the market, The Associated Press reported.
This is the second time in the past month that the FDA confirmed investigations into energy drinks.
In October, the FDA said Monster energy, another popular drink that contains even more caffeine, was allegedly linked to five deaths.