The thing is ED is a symptom of an underlying health issue - bad circulation .
If a man isnt getting enough bloodflow to retain or attain an erection, then he also isnt getting enough bloodflow to his heart, brain, organs...body.
Viagra is basically a bandaid to cover health issues that should be screaming to doctors "fix me" rather than blinding men into thinking its only got to do with their penis.
Viagra isn't fallproof either. At least 30%, ( or lilely more), of men who take it, - it doesn't work. If the enzymes and nutrients needed within the body for it to draw upon are at low levels, (like taurine), then it can't work....no matter how much a person takes.
Personally, id be ethical and market it like blood pressure tablets - "to be taken in conjuction with a healtheir lifestyle"
In fact blood pressure medication is one reason why some men lose their abilty to get an erection - it fakely lowers their blood pressure enough to live and avoid heart attack, but because its a fake lowering, they then cant raise their systolic pressure enough to achieve an erection.
Ergo - ED should be treated with improvement of health .... NOT a tablet .
Its not unheaed of for men to overdose with viagra to get hard .......and end up in cardiac arrest