Box Office Bomb: The film cost $25 million to make and Cannon expected it to be a blockbuster. Final box office gross: $11 million.
Executive Meddling: Tobe Hooper initially wanted to make Lifeforce a much sillier movie titled The Space Vampires, the same name as the book on which it is based. The execs forced him to make the story more serious, and switch to the present title.
When Tristar Pictures picked up the film for domestic distribution, they cut 15 minutes from the film and had some of Henry Mancini's score replaced with work by Michael Kamen. Due to the cuts, the US version is rather confusing at times.