Recreational use
Sildenafil's popularity with young adults has increased over the years.[20] Sildenafil's trade name, Viagra, is widely recognized in popular culture, and the drug's association with treating erectile dysfunction has led to its recreational use.[21] The reasons behind such use include the belief that the drug increases libido, improves sexual performance,[21] or permanently increases penis size.[22] Studies on the effects of viagra when used recreationally are limited, but suggest it has little effect when used by those not suffering from erectile dysfunction. In one study, a 25-mg dose was shown to cause no significant change in erectile quality, but did reduce the postejaculatory refractory time.[23] This study also noted a significant placebo effect in the control group.[23]