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 L carnitine cause fishy body odor? Surprising Truth and Solutions Tonum Compounded Carnitine (L) Injection Empower Pharmacy Do you or someone you love smell like fish? It could be Fish Odor Syndrome! #fishodorsyndrome #fishy #fishysmell #fishodor Breakthrough in studying the enzyme that ultimately produces fish odor syndrome EurekAlert!