I've been on synthroid for almost 2 years now. As a result of my last blood test, they upped my dosage to 75 mcg. I started getting symptoms around 5 months after completion of Rad treatments. The symptoms were a sudden 4 or 5 pound weight gain, sluggishness, and cold extremities. I felt cold all the time. I also had symptoms of what I thought was carpel tunnel syndrome in one wrist, but was told that it might have also been a symptom of the fried thyroid, as hypothyroid can cause fluid retention at the joints. After starting Synthroid, the joint pain cleared up, and I felt much better.

The symptoms returned a month ago, and sure enough, my blood tests showed a need to increase the synthroid dose. I don't remember being told to take it on an empty stomach, but I do remember instructions to not take a multivitamin which contains iron, as it would interfere with absorption. The multivitamin should be taken later in the day.

I found some good info at AllThyroid.org
Here's a link to the website:
http://www.tsh.org/index.html

It is a very easy side effect to manage. Synthroid has been around for more than 50 years,and is one of the most prescribed drugs in the world. The generics have not been around as long, and have gotten a lot of bad press about consistent dosing. My doc writes the script to be filled as written, and luckily, because it is relatively inexpensive, my drug plan dispenses Synthroid as the generic. I am to have another blood test after I have been on the new dosage for 6 weeks, and adjustments will be made based on that.

Hope this info helps.

Good Health,

Chuck