Does Carnitine Cause Body Odor? Lume Deodorant 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 Does Carnitine Cause Body Odor? Lume Deodorant Ronnie Coleman L Carnitine XS 4000, Orange Creamsicle, 15.72 fl oz (465 ml) Walmart.com 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