Started prozac (fluoxetine) 2 months ago. weight up about 2 lbs with no lifestyle change. heart, kidney, liver ok. is this probably prozac (fluoxetine)? or normal variation?

Hard to tell : Although a potential side side effect of Prozac (fluoxetine) is weight gain, it might be within normal limits for yourself depending on other factors that can influence daily/weekly fluctuations in weight. Would suggest continuing to monitor and report changes to your provider. Hope this helps - be well.

Not necessarily: When people are depressed they frequently have poor appetite and lose weight. So it stands to reason when their treatment ( in this case the effect of Prozac (fluoxetine) ) begins to work they may regain their appetite and start to gain weight. There are other potential reasons for gaining weight so this should be a topic of discussion with your doctor.