Ive been on a few cycles before and taken viagra during pct to help with an erection...but ive also taken it off cycle every once and awhile for special occasions and such...im 23 years old and i dont need to take it when i was off cycle but i figure every once and awhile wont hurt...well i took it 4 days ago and ive had sex everyday since then but yesterday i couldnt get an erection for the life of me and when i finally did it was weak and i barely lasted...the same thing happend to me tonight...at first i didnt think the viagra had anything to do with it since i did have sex days after i took it last but who knows...i was wondering if you guys think viagra might play a part in me not being able to perform since maybe im getting used to using it when i have sex or could it be i was just tired or stressed or some other reason??