I'm sorry to report that, despite it not being a wt gainer for some, it did cause me dramatic weight gain.   I guess you just have to try it.   I was disappointed to stop the medicine because it was amazingly helpful, but in addition to large weight gain,  I also had other things go on that were "atypical" -- or might have been warnings.  This was now over 10 yrs ago.   I was considered a "rapid responder", which should have been a warning that maybe a "manic" thing could happen.    I do have huge mood swings;  I'm not sure they were that bad before the prozac (but I think they were or I wouldn't have looked for the help).....but I now take other medication and feel much better.   I was unusual but not THAT unusual in what I know from others who have taken prozac and from my doctor.