Bad Girls from Valley High (2005)

Danielle is the leader of a clique of arrogant, mean high school girls; she and her rich friends Tiffany and Brooke care only about their pampered selves (although Brooke has periodic misgivings). No one really hangs out with them except a dumb jock named Gavin, and the class nerd Jonathan, and poor Danielle is getting nowhere with the popular guy Drew, even after she and friends accidentally killed his last girlfriend. It's been a year, and Drew still ignores her - but he doesn't ignore the new foreign exchange student Katarina. Since Katarina can't take a hint, Danielle begins plotting her downfall. But there's a slight problem: Danielle and her friends begin experiencing a level of high weirdness in which all three of them rapidly age. This serves to make Danielle more desperate than ever. She'll sacrifice anything, even Drew, to get her youth and looks back.