Frontiers Association between fatigue, peripheral serotonin, and L carnitine in hypothyroidism and in chronic fatigue syndrome Thorne Research L Carnitine L Carnitine Supplement The Natural Athletes Clinic How Does Carnitine Support Hashimoto's? Dr. Izabella Wentz 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. Acetyl L Carnitine