Mountain Dew is a popular carbonated drink made by PepsiCo.

What surprises many people is the level of caffeine in Mountain Dew - at 55mg it is significantly higher than Coca-cola.

The drink comes in a multitude of flavors and serving sizes and special additions.

Previously, in several countries outside the US, Mountain Dew contained no caffeine.

However, it was reported that in the beginning of 2012, places like Canada now sell caffeinated mountain dew as the principle product. Canada used to have a regulation that prevented the sale of non-cola sodas containing caffeine.