How Much Caffeine Is in Mountain Dew?
A 20-ounce bottle of Mountain Dew contains 91 milligrams of caffeine. Mountain Dew has more caffeine than competing soda brands such as Coke, Pepsi, Barq's Root Beer and Dr. Pepper, according to Mayo Clinic.
Mountain Dew ranks highest in caffeine content all among major soda brands, and a 20-ounce serving has a comparable amount of caffeine to energy drinks such as Red Bull and brewed coffee, according to Mayo Clinic. The Huffington Post notes that, as of 2014, Coke has twice attempted to rival Mountain Dew in the soda market with similar-tasting drinks containing less caffeine and has been unsuccessful.