I want to first give you the information we have here on Health Central about Celexa. You may find that information here.
And too...this is a really good question to ask your doctor. He or she will probably be able to tell you.
In researching your question I have found that people on various message boards say that it takes from anywhere from 2-6 weeks. It sounds like you should gradually taper off of it too so you don't have withdrawl symptoms.
Here is a message board where someone asks your same question.
I hope this helps! Thank you for your question.
How long does Celexa stay in your system after you stop taking it?