L Carnitine: Benefits, Uses, and Side Effects Lifespan Research Institute 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. TMAU: Diet to reduce a fishy odour Dietitian's Life Does Carnitine Cause Body Odor? Lume Deodorant Stabilizing the enzyme in fish odor syndrome Fish Odor Syndrome Springer Nature Link