Pam Grier's contract states that she must be in charge of doing her own hair for her films. For this film, she's wearing about three wigs blended together.
The line Courtney threatens Fern with in the bathroom ("I made you, and I can break you just as easily") is a homage to "The Rocky Horror Picture Show", and is the same line Dr. Frank-N-Furter uses to threaten Rocky, his creation, with.
Writer/director Darren Stein intentionally cast older actresses as the high school leads as an homage to films like Grease (1978) and Carrie (1976), which seemed to use actresses who were clearly in their mid-twenties.
Marilyn Manson was given his cameo part because he was engaged to Rose McGowan at the time the movie was made.
Each of the actors playing members of the Purr family was in either Carrie (1976) or The Rage: Carrie 2 (1999) while Judy Greer would later star in the remake of Carrie.
Writer/director Darren Stein originally intended to write a horror film. When he started writing the script, he based it on a group of girls he went to school with who would kidnap each other on their birthdays and thought, "What if that went horribly wrong?" In the process he eventually realized that he was actually writing a dark comedy.
The metallic hair bands wrapped around Rose McGowan's head for the prom scene was a result of off-screen competition. Rebecca Gayheart walked out of the hair and makeup trailer with her hair done up with flowers, which awoke the competitive spirit in Rose, who quickly went back into the trailer and demanded that she have a more interesting hairstyle.
Connie Francis tried to sue the producers of the film because her song "Lollipop Lips" is heard during a sex scene with Courtney and her boyfriend. This suit was dismissed.
Judy Greer said that when she was dressed as Fern, nobody on set paid her any attention. When she transformed into Vylette, all of a sudden everyone paid attention to her. However, the men on set seemed more timid while approaching her as Vylette.
Courtney's tattoo was actually Rose McGowan's real tattoo of herself. Initially they tried to cover it up with makeup, but it didn't work. Removing with CGI was too expensive, so they opted to leave it because it added more edge to Courtney's character.
During the entire film, a circular theme is visible, to call back to the jawbreaker. From the girls earrings (they wear hoops throughout the majority of the film), to light fixtures, to patterns, and wall fixtures.
The only line of dialog Liz Purr (Charlotte Ayanna) has in the whole film is, "What are you doing to me?" which is a recording from the birthday card.
The shot of Vylette sitting on the hood of her red corvette was inspired by the famous billboards of Angelyne that were seen around L.A. in the 80's and 90's.
Rose McGowan said that Judy Greer was much more of a Vylette than a Fern Mayo behind the scenes.
Rose McGowan based Courtney, whom she described as "a young, budding sociopath", on Gene Tierney's character in Leave Her to Heaven (1945).
Writer/director Darren Stein is featured in one of the yearbook photos that flash across the screen.
The character of Fern (Judy Greer) was inspired by Sissy Spacek's "Carrie" role (in which P.J. Soles and William Katt also appeared in). Greer played Ms. Desjardin in 2013's "Carrie" remake.
Rachael Leigh Cook auditioned for the role of Julie, reading the scene where the three girls discover Liz is dead.
Fern Mayo's stylish alter-ego Vylette was inspired by Vylette Fagerholm, Darren Stein's real life friend who appears in the film as "Make-Up Monger # 2".
Liz Purr's parents are portrayed by P.J. Soles and William Katt, who both appeared as popular teens in the horror film Carrie (1976). In Jawbreaker (1999), they are the parents of the most popular girl in school.
Rose McGowan and Rebecca Gayheart both appear in the Scream franchise. McGowan played Tatum Riley in Scream (1996) and Gayheart played Sorority Sister Lois in Scream 2 (1997). Julie Benz also appeared in a Scream-spoof called Shriek If You Know What I Did Last Friday the Thirteenth (2000).
In the scene where Courtney is changing Ferns name she says "a fern is a plant right? Well I don't know about you but I would much rather be a flower! A Rose is too obvious, never send a rose unless dyed black as a warning." This is ironic because The character of Courtney is named Rose in real life.