A Starbucks Frappuccino bottle contains roughly 95 milligrams of caffeine, which is about one-third the amount of caffeine you would find in a standard cup of coffee. Despite its smaller serving size, at nearly twice the concentration for coffee, Frappuccinos provide much more potent flavor and energy than regular brewed coffee. Therefore, if your goal is to get an intense boost of energy from your beverage then a Frappuccino might be preferable to a cup of coffee.