Association between fatigue, peripheral serotonin, and L carnitine in hypothyroidism and in chronic fatigue syndrome American ME and CFS Society 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. Does L Carnitine Work for Fat Loss? A Dietitian Explains L carnitine supplementation for the management of fatigue in patients with hypothyroidism on levothyroxine treatment: a randomized, double blind, placebo controlled trial. Semantic Scholar