Actually, because Lexapro is much newer than Celexa (thought they are pretty much the same drug at the foundation), who knows which will end up reporting the most side effects? There's a tremendous lag time of over a decade before we know how much a particular drug affects people. They are approved without any long-term human studies, so the first users are the guinea pigs. Just the way it is. But I would say you can't tell from the internet reports how many people are affected a particular way -- most people don't report their experience to their doctors, let alone the internet. I've taken both, and neither was a big weight gainer -- I mean, you're not talking Paxil or Remeron here -- but the effects differ by the individual, so only by trying the drug can you tell how it will affect you. Just because some of the molecule was cut out of Lexapro from the original Celexa, I'd guess that Lexapro is the lesser weight gainer overall, but that's just a blind guess, as nobody's really counting here.