Hi,
I have two prescriptions, one for the 0.5 and one for 1mg. I still have to get my labs checked every 2 weeks because my levels never stay the same. Over time, most people can reach a steady dose. I have a lot of trouble with my stomach which effects the elimination time, therefore dosage changes are made. The dose is affected by many things, other meds you may have to take, your kindey function, how well you are moving your bowels, how much you are drinking...it all adds up.
Good luck!
Fallon