Should I Take L Carnitine? NZProtein Stabilizing the enzyme in fish odor syndrome Liquid L Carnitine Core Nutritionals Does L carnitine cause fishy body odor? Surprising Truth and Solutions Tonum L Carnitine: Uses, Benefits, Dosage, and Side Effects StrengthLog 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.