L Carnitine for Fat Loss: Uses, Dosage, Benefits, and More MyDiagnostics If you are like a lot of people, you may have never heard of carnitine but this important nutrient is critical for our body's ability to optimally burn fat required for energy. The supplement secret for hyperthyroidism? , When dealing with hyperthyroidism or Graves disease, L carnitine can be a total game changer. It helps block the entry of thyroid hormone into the cell How Does Carnitine Support Hashimoto's? Dr. Izabella Wentz