celexa I've been on Celexa for over a year now. The most noticeable side effect has been significant weight gain (about 15-20 pounds). My doctor started me on Celexa after I had been going through numerous medical tests and I was getting depressed. I went off of it on my own for a time, but resumed taking it after my father passed away. I am currently on it now. Besides the weight gain and losing interest in sex... I wonder if that is worth it sometimes.