Studies that examine the effects of L carnitine on performance Download Table 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. Frontiers Association between fatigue, peripheral serotonin, and L carnitine in hypothyroidism and in chronic fatigue syndrome Optimizing endurance performance in elite swimmers: effects of L carnitine supplementation and hydration strategies Applied Water Science Springer Nature Link Acute L Carnitine Supplementation Does Not Improve CrossFit Performance: A Randomized, Double Blind, Placebo Controlled Crossover Study