I cannot imagine ANYONE gaining weight on Prozac. Its only been 2 days and I have hardly eaten ANYthing. I finally had to force myself to eat this morning at 1AM--I am too wired eat.....it reminds me of the 70's when I did speed(LOL) The truly awful thing is along with NO eating is the NO SLEEPING. I am already 118 lbs.....my main concern in taking a AD was weight gain..because of the horror stories, and frankly if I got fat again(I used to weigh 300 lbs, and have kept it off for 25 years) this would make me way more depressed then I already am. I guess everyones different, it seems to make quite a few people on this forum sleepy. I wish! I lost 10 pounds in 6 weeks and am down to 115. I just had no apetite. Sleeping was an absolute nightmare. I had to take ambien every night to sleep or else there was no chance. My doctor just took me off of it. I actually got a pretty bad rash from it.