Arginine by itself is often used as help for erection. It doesn't work wonders. But try taking a gram or two an hour or so before the event as well as your Viagra and it is, in my case , awesome.
"Oooooh it's hard and stiff." and
"It's FIRM."
It's cheap and safe and well worth trying. It may provide the missing link for those who don't get full results from V.
:)