Most people talk about carnitine like it is one supplement. It is not. Acetyl L carnitine and L carnitine L tartrate do different jobs, and picking the wrong one for the wrong goal is where people The Role of l Carnitine in Mitochondria, Prevention of Metabolic Inflexibility and Disease Initiation Did You Know? Some people report a fishy smell after supplementing with L carnitine. This happens because certain gut bacteria convert carnitine to trimethylamine, a malodorous compound found in rotting fish. Carnitine Deficiency: What Is It, Causes, Symptoms, and More Osmosis L Carnitine Linus Pauling Institute Oregon State University