Rx Item Levothyroxine 100% Powder(Non Sterile Pharmaceutical Grade ) 1Gm B GNC Total Lean L Carnitine 1000 mg 60 Tablets GNC Surprising Interactions with Levothyroxine (Synthroid) and Herbal Supplements De novo L carnitine biosynthesis. (A) Carnitine is synthesised from the Download Scientific Diagram L Carnitine Benefits Patients with Hypothyroidism Natural Health Research 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