Comprehensive review of the expanding roles of the carnitine pool in metabolic physiology: beyond fatty acid oxidation Journal of Translational Medicine Springer Nature Link Full article: Effects of high dose L carnitine supplementation on diaphragmatic function in patients with respiratory failure: A randomized clinical trial L carnitine supplementation for the management of fatigue in patients with hypothyroidism on levothyroxine treatment: a randomized, double blind, placebo controlled trial. Semantic Scholar 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