100% Pure L Carnitine by Genetix Nutrition Essentials Nutrition Warehouse Trimethylaminuria (Fish Odor Syndrome or TMAU) What Does Healthy Sperm Smell Like Conceive Plus 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. L carnitine supplements can cause a fishy odor in the breath, sweat, and urine. This is likely due to the formation of trimethylamine (TMA). TMA is also responsible for the pungent smell of Liquid L Carnitinees Amino Acids MYPROTEIN