I started on synthroid late last evening after endocrinologist urgently called in synthroid after my TSH went from .01 to 39 in one month. My free T4 is now .2 (hypo) coming down from hyper last month. (I had RAI 131 3 months ago!) He started me on synthroid 50 once a day and will give increase the dosage soon with me coming into the office next Thursday. I have to take this on an empty stomach and avoid foods/other meds for one hour. Does this sound like an appropriate dosage or will I need a lot more synthroid to feel better? I am also confused about t4 and t3 and if I will need anything other than synthroid.