When I took silodosin out of POIS, I felt extremely tired all the time. I too had the contractions, but didn't feel anything being released inside (or outside). Although I experienced orgasm (weaker than normal), it didn't leave me feeling satiated. After 3 weeks the sildosin failed to work and I experienced ejaculation (on a much reduced level). I suspect that this is the reason silodosin has not been more thoroughly researched as a male contraceptive - given the buildup of enough semen (or possibly sexual frustration), it doesn't work any more. It would be nice if some medical researchers could formally prove that silodosin does not work as a long-term contraceptive, but I suppose drug companies wouldn't be interested in funding that kind of research ...