Who knew little "Sabrina, the Teenage Witch" was such a rager?
Melissa Joan Hart is releasing a tell-all book where she opens up about her hardcore partying past, which included some heavy drug use and random hookups!
The book is appropriately titled "Melissa Explains It All," a play on Hart's popular '90s Nickelodeon show "Clarissa Explains it All."
"I experimented with weed, Ecstasy, mushrooms and mescaline for about a year and a half," the 37-year-old tells Life & Style.
One of her crazier nights out included taking Ecstasy at the Playboy mansion, making out with a girl in a limo and then heading to a Maxim shoot ... while she was still high!
Melissa says her partying past can be attributed to the people she was hanging out with at the time. "I was kind of running with a bad crowd," she tells the mag.
But after a few years in the Hollywood club scene, the actress admits "I just didn't enjoy taking drugs. I don’t like the loss of control."
Hart also says she hooked up with stars like Jerry O'Connell, Nick Carter and Ryan Reynolds -- who she cheated on her boyfriend with!
Are you interested in reading Hart's tell-all book?
And check out more good girls gone bad in the gallery below: