Too Much L Carnitine Smell Fishy TikTok 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. Will this make you smell like fish?! Pcos 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. 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. I'm a young woman with TMAU (Fishy Odor Syndrome) does anyone have some supplements suggestions for me? Yes I've been to the doctors, specialists and psych, they tell me nothing is wrong,