Alternate versions

Much of the gore has been edited out to get an R-rating in the United States and also for the UK release. The Spanish release is uncut.

The first cut of the film, which was released in Spain, contains hardly any gore and was more of a straight-up thriller. Most of the gore scenes were re-shot and added for the US and UK releases. Scenes that only appear in the original (Spain) version:

• After Jennifer escapes it shows a shotgun on the floor along with a blasted door
• Also after she escapes there's a scene that shows people wondering how she got out
• There's more investigating and police work with the two male cops and there's a also a female cop who doesn't appear in the other version
• Ben has an extra scene at a restaurant and more overall screen time Scenes that were added to the second (US/UK) version:
• The acid shower scene
• The flashback scenes with Gary and Ben as kids
• The blender scene
• The tooth-pulling scene
• Jennifer being abducted at the nightclub
• All of the dog scenes
• The scene where Jennifer is on her cell phone
• Jennifer and Gary fighting over the gun
• Jennifer shoots Gary an extra time (in his crotch)
• The videotape of the woman in the acid trap
• The scenes that show some of the aftermaths of the other victims

In Germany this film (based on the R-rated US version) was released on DVD by Sony in two versions: the uncut version with a SPIO/JK approval and a cut version with a "Not under 18" rating from the FSK which misses ca. 6 minutes.