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 The Role of L Carnitine in Kidney Disease and Related Metabolic Dysfunctions Role of carnitine in disease Nutrition & Metabolism Springer Nature Link Carnitine Deficiency: What Is It, Causes, Symptoms, and More Osmosis