The world's strongest coffee is now available in the United States, but it's not for the faint of heart.
- Black Insomnia has 58.6 milligrams of caffeine per ounce.
- That's almost three times the amount in a Starbuck's dark roast.
- A 12-ounce cup would have more than 700 milligrams of caffeine.
- The FDA recommends a limit of 400 milligrams per day.