Carnitine: the claims and why it may not work The adverse effects of long term l carnitine supplementation on liver and kidney function in rats L Liu, D M Zhang, M X Wang, C Y Fan, F Zhou, S J Wang, L D Kong, 2015 ByBv's Scoop of Knowledge Scoop 1: L Carnitine Better Knowledge Better Choices Better Version L Carnitine plays a crucial role in energy production by facilitating the conversion of fat into 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 Linus Pauling Institute Oregon State University