"this is by far the most effective antidepressant i have ever taken. i have tried prozac, zoloft, and celexa which all caused numerous unwanted side effects. i have been on effexor xr for a month and in the beginning the only side effect i experienced was being sleepy. this went away after about a week. i can tell you after just one week my mood lifted and i have zero anxiety. thank you effexor xr."