Even after you start adjusting
to the med and start seeing some improvements, it may still
take a little longer
to get
to the level of effectiveness you're after. And, if you ever decide to stop taking it, you need to ask your doc for a taper plan, as you should not stop taking it abruptly.
Good luck, let us know how it's going!
Some more info:
http://www.drugs.com/cymbalta.