There's a new article proving* that T4 hormone replacement (Levothyroxine) is inadequate for producing T3 in the body. Popular believe among doctors was that because T4 is converted into T3 in the cells of the body, and not produced by the thyroid, that all you needed to replace was T4. Not so, says a paper published in the Journal for Clinical Endocrinol Metabolism. The big payoffs for adding T3? Well, weight loss and lower cholesterol, "without detected differences in cardiovascular function or insulin sensitivity."
Damn. Probably shouldn't have let my old doctor talk me into stop taking it years back. Time to call the new one.