underactive thyroid
"This medication is used to treat low thyroid hormone levels.  I have Hashimoto's. This is an autoimmune disorder where the body attacks the thyroid until it no longer functions properly.  Many people with low thyroid hormone levels have this but are not aware because doctors tend to treat with the medication rather than the whole disease.  A lot of the people posting claiming side effects are actually describing side effects of LOW THYROID or HIGH THYROID!  The medication is simply a replacement hormone and will not make you constipated, have brain fog, anxiety, fibromyalgia, heart palpitations, etc. unless you are taking TOO MUCH or TOO LITTLE of the hormone. A lot of the negative reviews of this medication are absolutely ridiculous!"