I've not read every post in this thread, only a few but here is my contribution.
In my occupation as a WG I have a suspicion that more men than we think use Viagra or other Pharmaceutical Arousal Aids. I shall call them PAA for simplification purposes. Whilst they are useful and very successful for many men I would like to report the following;
One guy who had to be signed off work sick for 6 months after trying Viagra on prescription from his GP.
Another guy reported constant blinding headache and visual disturbances (flashing lights, that sort of thing) for up to 1 week after taking his first dose, which once again had been prescribed by his GP following a proper assessment. This chap then went on to visit a Chinese Herbal shop, obtained the 'natural' equivalent and experienced the same debilitating effect. I've also been able to spot a few PAA users by their red eyes and flushed face - when asked they have confirmed my suspicions and or usage.
I have also been asked upon enquiry if I'll supply viagra as part of a booking.
My stance is this;
PAAs are great for the men they work for, and who can take them with no ill effects. There does appear to be a minority for whom PAAs do cause some side effects - and remember these were guys for whom health issues had been ruled out. So some caution should be applied. I won't be obtaining nor administering anything stronger than aspirin, and that will be after asking whether or not you have suffered from any stomach conditions(and I am a qualified, insured First Aider).
By the way I don't judge a guy by his PAA use, as long as it's safe and works for him.