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 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. Comprehensive review of the expanding roles of the carnitine pool in metabolic physiology: beyond fatty acid oxidation Journal of Translational Medicine Springer Nature Link Carnitine: Health Benefits, Supplement Uses, Side Effects, Daily Intake L Carnitine Uses, Benefits, and Side Effects thegoodbug