Frontiers Association between fatigue, peripheral serotonin, and L carnitine in hypothyroidism and in chronic fatigue syndrome Carnitine can be a game changer for those with NF. It helps build muscle, improves learning problems, and reduces nerve pain. Who takes it? Frontiers Age and APOE affect L carnitine system metabolites in the brain in the APOE TR model The Science of Carnitine: How It Works and Why It Matters Losing weight with L carnitine supplements. Yes or no?