Isla Fisher Leads a Sexual Revolution In Hollywood.

The pint-sized Australian redhead isn't burning bras, but is challenging the film studio system to make comedies starring women.

Studios will greenlight a comedy if they can attach a Jim Carrey, Adam Sandler, Will Ferrell, Ben Stiller or more than 10 other comedians, but are reluctant to produce a comedy with an actress as the lead.

"I realised after Wedding Crashers there aren't that many comic opportunities for women in Hollywood," Fisher, who was the breakout star of Wedding Crashers, a 2005 comedy headlined by Owen Wilson and Vince Vaughn, told AAP.

"All the scripts are for men and you play 'the girl'."

Fisher, 31, who is expecting her first child with another Hollywood comedic titan, British born Sacha Baron Cohen -- recently better known as Borat -- is using her new found clout to write and produce comedies for women.

Studios have bought two of her projects -- Groupies and The Cookie Queen.

Groupies, which she will star in with Saturday Night Live comedienne Amy Poehler, is about two women infatuated with a band. They stalk its members and think the band is equally besotted by them, but the band could not care less.

The Cookie Queen is about a girl scout, aged in her 30s, who has held the record for cookie sales for 20 straight years.

"I found some great writers and I kind have been developing some things for myself and pitching it to studios," Fisher explained.

"That's been really rewarding and relieving because it means I will get opportunities to go and do that.

"I just think there are so many great female comediennes in Hollywood.

"I love Amy Poehler and Sara Silverman.

"It's just a shame there are not that many opportunities."

Australians will next see Fisher in the Hollywood comedy, Hot Rod, where she plays the love interest of the male lead, another Saturday Night Live star, Andy Samberg.

Samberg's character is a dim-witted wannabe stuntman who rides around his small town on a bike while wearing a blue stunt outfit and yellow cape.

His moment of truth comes when he plans to jump 15 buses to raise $50,000 for a life-saving operation for his ailing, but abusive, father.