Viagra was developed as a treatment for high blood pressure. Patients taking it for that noticed the “side effect” kept coming up.
Oh, Behave!
Viagra also helps prevent dementia and all sorts of organ conditions by increasing blood flow throughout the body.
As the story goes, when developing the trials that the people taking the drug refused to turn in leftover tablets.
It didn't take doctors long to figure out why they wanted to hang on to them.