I've only been on Effexor for about a month; 75 mg daily. The only "bad" side effect I've felt so far is that I feel the room is too warm, even when others are okay with the temperature. The "good" side effect, contrary to what so many have posted here, is that for the first time in my life (I'm in my mid 40s), I am NOT having nightmares/night terrors. I've been plagued by these all my life, anywhere from several a night (during really bad spells) to a few a week (during good spells). For the last month, since getting on Effexor, I have not had a single nightmare and I've slept soundly, without waking up either paralyzed with fear, screaming, or thrashing about in the bed.