Viagra is becoming a party drug, research suggests.
One recreational user involved in the Health Research Council funded study said he was addicted to the sex drug.
Tiina Vares and fellow researchers Annie Potts and Victoria Grace - all from Canterbury University's gender studies department - and University of Auckland psychologist Nicola
Gavey are in the final year of a three-year study into the "sociocultural implications" of Viagra and similar drugs.
Ms Vares said researchers suspected recreational use of the drug, intended for men with erectile problems, is high.
One man involved in the study had admitted he not only used it recreationally but was addicted to it.
"He said it was more addictive than heroin," Ms Vares said.
"It was a psychological addiction. He said he never had to worry about his performance."
The man said Viagra was used widely in gay clubs and the broader nightclub scene.
"It's become just one more pill you add to your party pack."
Even television portrayals of the drug, monitored by media focus groups set up as part of the study last year, showed recreational rather than medical use.
Ms Vares said the study's focus groups had shown that advertising for Viagra had raised male anxiety about sexual performance - even among men in their 20s.
Viagra has been marketed here now for more than four years.
Ms Vares said that over time the advertisements had portrayed younger and younger men.
The focus groups saw them as trading on men's fear that they were not performing well sexually.
"It had even got the young men scrutinising their performance," she said.
- NZPA
