I've noticed that they are warning that the use of some of this stuff might cause the occasional four-hour trouser tent and if it does, you should report to the sawbones right away. Heck, when I was in school I used to sport one of those for six hours or more. There was just something about all them curvy, good lookin... Uh hmm--anyway, I don't know if that's progress or not--puttin all of that into a pill. I still prefer the old fashioned method.
There is one ad though that talks about keeping you ready to go for 36 hours. I think they must have invented this one for those who are running a harem.