I have been on 20mg for over 11 years. I am a big guy to begin with (6ft - 250lbs - former football player) and I think I may have gained about 10-15lbs initially. However, it may have been the anxiety / depression that created this as I really just stayed indoors for 6 months hoping the feelings would go away
I have long since lost that weight gain. I also had initial side effects of dry mouth, slightly increased anxiety and minor insomnia. This last about 2 months and I knew this was going to happen (based on feedback from my doc), so I didn't get too worried. I honestly have no side effects at all now.
Lastly, I did successfully wean off Paxil about 3 years ago. Many have complained that the withdrawal symptoms of Paxil are really bad. My opinion is they tried to wean off too quickly. I took 6 months to wean off and had NO withdrawal symptoms.
Unfortunately, my anxiety came back in about 8 months so I went back on the Paxil. Feeling great again for the last 2+ years!!!