'American Ultra' trivia and fun facts

Kristen Stewart dyed her hair bright red for the film.

Uma Thurman was cast but her deal never materialized and Sharon Stone replaced her. When scheduling issues caused Stone to drop out, Connie Britton stepped into the part.

Author Stephen King said via Twitter that he loved "American Ultra" and called it, "fresh and exciting. Very cool."

As a promotional stunt, Lionsgate gave away/delivered free marijuana at the San Diego Comic Con to anyone with a medical marijuana card.

Jesse Eisenberg and Kristen Stewart previously co-starred in the movie Adventureland (2009).

Jesse Eisenberg and Kristen Stewart previously starred in Adventureland (2009). In both movies, Jesse Eisenberg's character is known for his association with marijuana.