Didn't another study show carnitine was good for the heart? Thyroid medication use as an assisted bodybuilder should be approached with caution and based strictly on individual neednot just because it's what you do during prep. Too often, both competitors and non competitors L Carnitine and Levothyroxine: A Critical Interaction Warning Anabolic Planner This medication is one of the most commonly prescribed medications for thyroid dysfunction. I'm talking about levothyroxine. And while it may silence symptoms for a time, it doesn't heal the thyroidand it L carnitine reduces hyperthyroidism symptoms There are 3 main types of thyroid medications available T4 T3 (usually combined with T4) NDT desiccated thyroid (a combination of T4 + T3) Most are widely available