Amanda Bynes' character, Penny, is seen constantly eating lollipops. Her father, who is a dentist, became very worried for Amanda's dental health, as it was estimated she ate about 40 lollipops a day. Amanda told him that she wasn't really eating all of them, when in reality she ate them all.
This film brings together John Travolta who starred in Grease (1978), and Michelle Pfeiffer who starred in Grease 2 (1982). One day, while the cast was waiting between takes, Travolta began singing "Summer Nights". Co-stars Amanda Bynes and Zac Efron were so excited that they immediately began sending text messages to their friends about what was happening.
Most of the cast jokingly called "You Can't Stop the Beat" "you can't stop to breathe" because of its pace and fast-moving lyrics. Queen Latifah said she had no trouble singing a lot of words very quickly because of her background as a rapper.
After Penny and Seaweed fall in love, she sings, "And if they try to stop us, Seaweed/We'll call the N-double A-C-P." Until the Supreme Court's 1967 decision in Loving v. Virginia, interracial marriage was illegal in 17 states, including Maryland. In Baltimore, Maryland, in 1962, Seaweed and Penny's relationship was illegal.
Costume designer Rita Ryack actually got vintage outfits for some of the characters to wear during a number of the scenes shot in the high school. Link Larkin's blue sweater was a sweater vest found at a vintage shop.
According to Film Journal International, the song "Big, Blonde and Beautiful (Reprise)" was added in as at the suggestion of Michelle Pfeiffer to replace a scripted scene, giving her the chance to sing.
The creative team modified several songs from the Original Broadway production, removed others, and added some new songs. "Mama, I'm a Big Girl Now", a number performed in the stage musical by Tracy, Penny, and Amber opposite their respective mothers, was reluctantly cut from the script during pre-production - but was sung over the credits by all three "original" Tracys (Ricki Lake, Marissa Jaret Winokur, and Nikki Blonsky). While the crew liked the song, screenwriter Leslie Dixon felt the number did not adequately advance the plot, and would also be impossible to film without a three-way split screen, which neither she nor director Adam Shankman wanted to use. "It Takes Two", sung in the stage musical by Link to Tracy during her first day on "The Corny Collins Show", was moved to an earlier scene in the film; Link sings it just before Tracy learns that the TV station will be holding auditions for a new Council Member. However, only the song's coda remains in the final release. "Cooties", performed by Amber at the climactic "Miss Teenage Hairspray" pageant in the stage musical, is an instrumental during the pageant contestants' dance-off. "Mama" and "It Takes Two" are also instrumentals during scenes featuring broadcasts of "The Corny Collins Show". A reprise of "Big, Blond, and Beautiful", sung by Velma and Edna, was added to the film as part of a new subplot involving Velma Von Tussle's attempt to seduce Tracy's father Wilbur. "I Can Wait", a climactic ballad written for the film, was to have been performed by Tracy as she is hiding out in Penny's basement. The sequence was cut from the final release print. "The New Girl in Town" was written for the stage musical, dropped during the workshopping stage, resurrected, and used in this film to underscore Tracy's rise-to-fame montage, and to show "The Corny Collins Show" on Negro Day. "Ladies' Choice", performed by Link at a school dance, was added to replace "The Madison", a dance number carried over into the stage musical from Hairspray (1988). "Come So Far (Got So Far to Go)" was written for the film for use during the closing credits.
In a classroom scene, a teacher mentions that Everest is not Earth's highest geographical point. She asks what the actual highest point is, and the bell rings. The answer is Mt. Chimborazo in Ecuador, which is the furthest point from the Earth's center, but closer to local sea level than Everest. (The Earth bulges at the equator.) However, as the movie is set in 1962, and the analysis that led to Mt. Chimborazo being described that way was performed recently, it is extraordinarily unlikely that's what the teacher is referring to. Also, by the measurement that lists Mt. Chimborazo is highest, Everest is not 2nd, but 10th. Almost certainly, the reference is to K2, which is a point of contention.
The soundtrack for the new "Hairspray" features a rendition of all of the "original" Tracys (Ricki Lake from the first film, Marissa Jaret Winokur from the Broadway cast, and Nikki Blonsky from this film) singing "Mama, I'm A Big Girl Now". Harvey Fierstein appears near the end, but he isn't credited.
Four songs were written for the film, but didn't make the final cut: "I Can Wait" (the only one filmed, available on Special Edition DVD), "Mrs. Von Tussle Says" (meant to replace Miss Baltimore Crabs), "Save Your Applause 'Till The End" (Velma follows Tracy around, complaining), and "Turn Back The Hands of Time" (Original "Come So Far"). All 4 songs are on the 2-Disc Special Edition Soundtrack.
It wasn't until half way during production that Michelle Pfieffer realized that her character was a racist. She became worried about what people would think. But the director calmed her down and she continued the movie.
The trivia items below may give away important plot points.
The song "You Can't Stop the Beat" was changed for the movie version. When it is performed of Broadway the last verse is sung by Velma and Amber von Tussel, providing a form of redemption for the villainous characters. This does not happen in the movie. The Broadway lyrics are: Ever since we first saw the sun/It seems von Tussel girls are always Tryin' to please someone/But now we're gonna shake and shimmy it/And have some fun Today!" In the movie this is changed to: "Ever since we first saw the sun/a man and woman liked to shake it when the day is done/And so I'm going to shake and shimmy and have some fun today."