Australian teenagers are having half as much sex as their parents because of social media, dating apps and pornography, according to experts.

Around 40 per cent of people between 18 and 24 have never had sex and 15 per cent have sex once a month compared to the 40 to 49 age range with 30 per cent having sex once a month, according to the Australia Talks survey of 50,000 people.

Sexologist Jacqueline Hellyer said teenagers are substituting online contact for the real world and could be losing the ability to communicate face-to-face.

Around 40 per cent of people between 18 and 24 have never had sex and 15 per cent have sex once a month compared to the 40 to 49 age range with 30 per cent having sex once a month (stock)

'Communicating with potential dates via text means young adults are missing out on tone, body language and human contact that comes with meeting in real life,' Ms Hellyer told the Daily Telegraph.

Susan Tuckwell, a sex therapist in Sydney, said online pornography was changing how people get aroused.

She said some people 'can only be aroused by pornographic images' while others can't take their relationships from the digital world to the real one.

'They are sitting on their devices getting a little bit titillated but for some reason when it comes to making direct human contact it's too anxiety-producing,' she said.

Ms Hellyer echoed the sentiment by saying dating apps presented an endless stream of options that created choice paralysis.

Another reasons teenagers aren't having sex is because they're scared of what they look like naked.

Susan Tuckwell, a sex therapist in Sydney, said online pornography is changing how people get aroused (stock image)

The sex experts said pornography created concerns that sex was should only take place between two 'beautiful' people, fuelling cosmetic surgery procedures such as labiaplasty.

'The ideal woman is meant to look like a breastfeeding mum up from the waist up and a pre-pubescent child from the waist down,' Ms Hellyer said.

Ms Tuckwell said women are now so concerned about positioning themselves so they look best during lovemaking that they have lost focus on getting pleasure from having sex.