Hi, I had a lot of negative side effects when I was prescribed Synthroid. The dosage was changed multiple times to determine if the side effects were due to too high/low of a dose but the side effects remained. I stopped taking Synthroid and the extreme side effects stopped. My numbers were good so it was very hard to figure out what was related to the medication itself; once I stopped taking it, the improvement seemed to support that it was the medicine. I had always thought everyone on Synthroid got a prescription and everything improved…this was not the case. My doctor told me that a lot of people have problems with Synthroid. I am currently on Levoxyl. Although I have some negative side effects, the doctor has been trying to tweak my dose to eliminate them. I had a recent increase in thyroid related issues (due to stress) so the doctor increased my dose. The issues decreased however very shortly after the side effects increased again. The doctor just decreased my dose again and the side effects seem to be improving again. I have a history of difficulties with side effects from medications however the thyroid issues seem to be much more sensitive to changes in dose, stress, etc.
It should be noted that stress and specific foods can change how the thyroid works, so sometimes things will change dramatically and side effects will manifest due to a combination of changes. My doctor said that I seem to be very sensitive to the side effects of the medicine so small changes can bring out or remove side effects. Good luck!