Viagra...

I'm not sure how it works, but I've heard that you have to swallow it quickly, otherwise you get a stiff neck.

bump.

thankfully I have no need for it yet.

I don't know the details, except that when my husband took it due to blood pressure and anti depressants, it worked.
The key thing to remember is that it will help with erectile dysfunction but the rest is up to the one taking it.
It will work if your mind is on sex as though in a regular relationship type of mood. If it takes stimulation to get your penis erect, then do it. It will allow you to not lose this erection like you might if you don't take it.