Week 3 of Paxil 20mg. My side effects at the beginning were awful, anxiety was worse and I couldn't sleep, sit still, racing thoughts.It's slowly progressing, very slowly. But I still have some side effects. I took it over 10 years ago and it worked wonders but I forget how long it took to work. I don't plan on being on it forever. But my question is, how long does it usually take to work? My dr said 4-6 weeks. I didn't expect it to be magic but I can't wait for full on relief so I can clear my mind and work on myself without having all this craziness to go along with it :)