underactive thyroid
"I can almost guarantee that most of these negative reviews are due to either 

1. Taking the medication incorrectly (generic works for some not all), too close to food or iron,calcium, some antidepressants interfere)



2. Taking the incorrect dose 



3. Not being consistent(must be close to the same time daily )



I had gone through many changes before finally getting it right. Seems to be working good after getting on brand name and taking it seriously."