A guy friend on mine (more a penpal than a real friend: I have only seen him three times since I first met him over 15 years ago, but we are on email daily) with Bipolar II really needs Effexor to help with low mood, but he suffers from anhedonic ejaculation as a side effect. And that is a really bad side effect.

In women, I do not know if effexor causes sexual side effects. But apparently in men, it is known for that.