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, Does L carnitine cause fishy body odor? Surprising Truth and Solutions Tonum 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