Mountain Dew Wiki
Mountain Dew Wiki
Mountain Dew MDX
Mountain Dew MDX Logo.png
Mountain Dew MDX's logo.
Flavor: Citrus
Color: Yellow-Green      
Current Status: Discontinued
Locations Available: United States
Year(s) Available: 2005 - 2007
Similar Flavors: Adrenaline
Mountain Dew AMP
Dew Fuel
Amp Energy
Mountain Dew Citrus Blast
Kickstart (Energizing Original Dew)
Kickstart Ultra (Energizing Original Dew)
Game Fuel (Charged Original Dew)

Mountain Dew MDX (previously known as "Flavor #516" and "Mountain Dew X") was a Mountain Dew energy drink variant that lasted from November 2005 and until mid-2007. It was PepsiCo's attempt to compete with Coca-Cola's Vault energy drink.


MDX was the original Mountain Dew flavor formula, but with ingredients added such as maltodextrin, ginseng, taurine, d-ribose, and guarana to give it the energy drink kick. It also had a higher caffeine content than original Mountain Dew, despite having the same basic taste and color.


  • This was one of many attempts at a Mountain Dew energy drink. See "Similar Flavors" in the infobox for more.
  • MDX was the pioneering flavor for the Sidekick bottle design, which PepsiCo would incorporate into most of their 20 oz. bottle designs later on in the 2010s, replacing the dome-like design.