The key to the new film Hysteria was treading a fine line between humour and more serious commentary about female sexuality, said the director and stars of the comedy, which is loosely based on the origins of the vibrator.

On the surface, the Victorian-era film is laden with double-entendres and winking dialogue in its tale about a struggling, modern-minded young doctor (Hugh Dancy), who is enlisted by a senior physician to bolster the latter's very successful — and exhausting — practice treating hysteria in wealthy women through below-the-waist "massage."

"The trick and the pleasure, but also the difficulty, was charting the course between the parts of the movie that we are taking more seriously and the stuff that is more knockabout and fun, and to try to make sure they’re all in the same film," Dancy said at the Toronto international Film Festival on Thursday, at a press conference that shifted between lighter moments of humour and weightier discussions about sexuality.

"This movie is about a lot of things. Mostly it’s fun," said the film's director, Tanya Wexler. "[But] in many ways it’s about being able to choose your own destiny, whether doctor or patient… The more woman can make their own choices about anything, the more we can enjoy ourselves."

Playing a passionate and progressive-minded woman named Charlotte fighting against the era's diminished perception of her gender, actress Maggie Gyllenhaal offers a modern access point for viewers. The main cast is rounded out by Rupert Everett and Felicity Jones.

"The situation that's happening in the movie is so outrageous and ridiculous from our contemporary point of view. The things that Charlotte says [about equality for women] are so simple, politically. They’re things that we all agree with and we all know now," she said.

"A lot of the movies I make have a lot to do with sexuality and it’s because I’m interested in sexuality and so is everybody else. Film can be — and has been for me — an opportunity to explore and think about sex as well as many, many other things."

For Dancy, the most outrageous aspect of the project wasn't the vibrator itself or the scenes of women having orgasms, but a basic fact on which the film is based: that the male medical establishment of the time had wrapped a multitude of women's symptoms, general attitudes and lack of fulfilment into a catch-all, fictitious condition.

"At the source of all the comedy and the source of the more serious stuff is the fact that medical men were seriously — without any irony, without any deception — diagnosing this non-existent condition [of hysteria] and doing what we’re doing manually and totally failing to see that there was anything sexual about it. That’s astonishing," he said.

Even now, however, society remains nervous about discussing female sexuality, Gyllenhaal added.

"We’re all sort of blushing and giggling about these women [climaxing]," Gyllenhaal said. "I don’t think people really do talk about it very much. I think it does still make us kind of blush and feel uncomfortable."

Wexler recounted the exuberant reaction she received from a female flight attendant after showing her the Hysteria trailer, while on her way to Toronto. It was further indication, the director said, that there's still a lack of interesting stories about women that make it into movie theatres.

"A lot of women are interested in getting married. [But] there are a lot of other topics women are interested in, too… There’s a real appetite to see your experience or some version of your story reflected back. And I think right now a lot of women’s experience is underserved."