Blue Shock is a Mountain Dew Freeze/Slurpee Flavor exclusively available 7-Elevens in Slurpee machines that were released at the start of June 2002 and later released throughout some gas station convenience stores in the United States.
Blue Shock is a Berry Citrus (strongly resembling a blueberry) flavor of Mountain Dew. It's similar to another Dew flavor, which has a similar shade of Berry Citrus flavor, Voltage. Its color, as its name implies, has a Cobalt Blue look. Unlike most Mountain Dew varieties, Blue Shock lacks Caffeine, however the Asian releases of the drink do contain Caffeine.
Original 7-Eleven Slurpee Release
At the start of June 2002, the flavor was first exclusively released to 7-Eleven convenience stores in the United States for the summer of 2002 as a Slurpee drink. This release potentially replaced Code Red Slurpees as it also got released for the summer a year before Blue Shock.
Right after its release, it got heavily promoted in its advertising in commercials, a few more other promotional materials for the Slurpee drink in general. It bumped its popularity quite a bit during its first few months and a few months after its release. Its name got a rework, renamed from "Mountain Dew Blue Shock" to "Blue Shock Freeze."
Since 2002, Blue Shock has been in 7-Elevens throughout as a consistent Slurpee permanent flavor. As of October 2021, Blue Shock is still available as a Slurpee.
Circle K Release
Sometime in the early 2010s, Blue Shock got later released in Circle Ks as a Froster Freeze. As of right now, there is not much information known about this particular release.
Royal Farms Release
In 2020, Blue Shock got later released in Royal Farms as a Freeze. As of right now, there is not much information known about this particular release.
In 2014, DEWmocracy Malaysia took place. This promotion held an opportunity for newcomer Blue Shock alongside existing varieties LiveWire, and Pitch Black, to be the next permanent Dew flavor in a national voting session for fans to vote on their favorite of the three flavors. After a steady battle between the three Dew flavors, Blue Shock was announced as the winner. Despite the verdict of the outcome, all three flavors remain available.
As of 2021, this flavor is currently listed as an offering on Etika Holdings' website. 
In 2016, DEWmocracy Philippines took place, and with that Blue Shock was introduced into the country. The promotion pitted the drink against existing variety LiveWire, to be the next permanent Dew flavor in a national voting session for fans to vote on their favorite of the two flavors. Strangely enough, no winner was announced, and both Dew flavors were discontinued the following year.
On May 26, 2015, following their Avengers: Age of Ultron promotion, the Mountain Dew Singapore Facebook page announced the release of Blue Shock in the country as a 7-Eleven exclusive.
In 2020, the drink was removed as a listing on Etika Holdings' website and is no longer displayed on Mountain Dew's social media profiles, meaning that the flavor has been discontinued in the country. 
In 2016, DEWmocracy Pakistan took place, which introduced Blue Shock, LiveWire, and Pitch Black into the country. The promotion pitted all three flavors in a battle to be the next permanent Dew flavor in a national voting session for fans to vote on their favorite of the three flavors. After a steady battle between the three Dew flavors, Blue Shock and LiveWire lost to Pitch Black in a live announcement on August 1, 2016, and it was discontinued shortly afterwards.
- In 2002 in the United States, since this release was old, there wasn't any evidence that this release, in particular, is a Freeze release or a soda fountain release in general. Because of this, many rumors began exaggerated circulating of its release.