"horrible experience, although everyone is different. i was on 150mg, i am currently tapering off while switching to welbutrin. with effexor  tapering is necessary. i&#039;ve tried going off cold turkey and the withdrawals are like nothing i&#039;ve ever experience. i had intense brain zaps (google it), flu like symptoms, could easily sleep half a day away. even if you miss one day, you experience these withdrawal symptoms. while on it, it only worked somewhat well for a month or so. i experienced light nausea which went away. i also experienced impotence and unable to climax which has not gone away. now that i&#039;m tapering and introducing welbutrin the sexual side effects seem to be getting better."