I was put on 100mcg of levothyroxine for a small benign nodule on my thyroid. I had a normal range FT4 and a low TSH at time time I was put on the meds. After 10 months I went to hyperthyroidism. I have not had the levo for 10 weeks now. I am now on 25mg of atenolol twice daily to control the rapid heart rate. I was just put on 10mg daily of methimazole for 3 weeks, then reduce to 5mg daily. I was told that it may take over a year for my body to get over all of the side effects since my symptoms were due to iatrogenic (meaning medication induced). Has anyone else had this problem, and if so how long before did it take for body to return to "your" normal.