The study involved over 3,000 men who answered questions including about how often they had sex, how regularly they masturbated, and how long and often they watched porn.
Men reporting erectile dysfunction faced a hazard ratio of 1.4 even when testosterone levels were healthy, the study authors state.
The men, aged between 38 to 57-years-old, had all taken the drug for the first time.
Men looking for a natural alternative to Viagra are munching on lichen they find on the sidewalk. But botanists warn it's toxic.
The British Medical Journal report said it was "unusual" that no staff questioned giving the prescription to a female patient.
The man ingested far more than the recommended dose.
Researchers studied a group of older men who had lower rates of sexual dysfunction than their peers.
Restaurant shot to fame after refusing to serve White House press secretary Sarah Huckabee Sanders.
Twenty years after Viagra's approval, the FDA is scrambling to catch dangerous impostors.
Finasteride can cause "debilitating sexual dysfunction" resistant to Viagra.
Nearly half of the male participants studied reported getting an erection within five minutes.
Is it time to give away the household pet?
New radiation-shielding briefs may just save your sperm