Research suggests more Australian teenagers are viewing porn and doing so at a younger age than ever.

Almost 90 per cent of Australians aged 15-29 living in Victoria have viewed porn at some point, with men starting earlier (median 13-years-old) than women (16-years-old), according to the new study.

The researchers found that people who viewed the most porn (and those who viewed it from a younger age) were more likely to be male younger, have a higher education be non-heterosexual in identity and have recent mental health problems.

“We're not out to prove that watching porn is a bad thing. But definitely watching pornography more frequently is associated with some negative outcomes such as poor mental health, though we can't say from this study if one is causing the other,” Burnet Institute researcher Dr Megan Lim said.

Since porn use is common and frequent among young people from a young age, this needs to be considered in sexuality education, the researchers say.