Undated -- When you get up in the morning, you may need a little something extra to get you going. Some of us reach for coffee, some reach for soft drinks or sodas, and some reach for energy drinks.
They can all give you a boost. According to the Mayo clinic, a soda can have 30 to 35 milligrams of caffeine. They also say a cup of generic instant coffee can have any where between 27 and 173 milligrams of caffeine. But get this, a 16 ounce Monster is can have up to 160 milligrams of caffeine in it. And that's what's causing problems.
Monster Energy drinks have been cited in five deaths reported to the Food and Drug Administration. The FDA says it has not established a direct link in any case and it's still investigating.
But 14-year-old Anais Fournier died in December 2011. Her heart stopped after she drank two 24-ounce Monster energy drinks in less than 24 hours. The coroner's report says she died of caffeine toxicity in the setting of a cardiac arrhythmia.
The coroner also said Fournier had a mild underlying heart condition -- like 10 percent of the population.
Again, the FDA is investigating five deaths and one heart attack potentially linked to the energy drink over the past three years.
In a 2008 study -- researchers called for prominent labels on all energy drinks warning of health risks-- including caffeine intoxication.
As a note-- Monster does have a warning on their can. It says consume responsibly - limit three cans per day.
CBS News/Mayo Clinic