Synthroid Side Effects: Well....I had missed a few days of my synthroid because I was on http://www.medications.com/effect/view/9980 Well....I had missed a few days of my synthroid because I was on vacation, and started to feel really sluggish and just "off". I had a thyroidectomy a few years ago due to a growth in my thyroid that was only getting bigger. So...after reading all of these, when I stopped taking my thyroid medicine, synthroid, my body sta Mon, 16 Mar 2009 19:33:52 -0400 http://www.medications.com/effect/view/9980?item=18089 when I stopped taking my thyroid medicine, synthroid, my body started slowing down . I now have diabetes. http://www.medications.com/effect/view/9980?item=18089