autoimmune thyroid disease leading to hypothyroidism is the most common autoimmune disease in the US. Most patients are forced on t4 only medications. A normal healthy thyroid puts out 80% t4 and 20% t3. And out of the millions and millions of patients on thyroid replacement a huge portion of them are left sick and miserable for the rest of their lives,even with a normalized TSH. They experience continued debilitating fatigue, excessive weight gain, inability to lose weight, joint and muscle pain and more, all with a normal TSH. Something is wrong with what you’re doing. Maybe TSH is the wrong lab value to look at, maybe the body doesn’t make or receive t3 the way you think it does. Maybe there are completely unidentified biological factors involved that have not been discovered yet. But I can promise that anyone who figures this problem out and conducts the proper peer reviewed studies, you will have a drug that will fly off the shelves. T4 only isn’t working for a massive population of patients.