Does L carnitine cause fishy body odor? Surprising Truth and Solutions Tonum L Carnitine Is it Worth Taking? Ideal Nutrition L Carnitine: Unveiling the Science Behind its Role in Effective Weight Loss Aesthetics 360 Lash & MedSpa L Carnitine: Benefits, Side Effects, And Dosage, Per Dietitians 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.