Frontiers The Effects of L Carnitine, Acetyl L Carnitine, and Propionyl L Carnitine on Body Mass in Type 2 Diabetes Mellitus Patients Early research into L carnitine was often cited as underwhelming, showing negligible changes in muscle carnitine content and fat loss outcomes. However, these findings may have been limited by a short study window L Carnitine is one of the most hyped weight loss supplements online but here's what most won't tell you: Your body naturally produces L Carnitine using amino acids l, and a healthy person usually Comprehensive review of the expanding roles of the carnitine pool in metabolic physiology: beyond fatty acid oxidation Journal of Translational Medicine Springer Nature Link