Do you or someone you love smell like fish? It could be Fish Odor Syndrome! #fishodorsyndrome #fishy #fishysmell #fishodor Potential Adverse Effects of L Carnitine Marnys 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 Malodorous biogenic amines in Escherichia coli caused urinary tract infections in womena metabolomics approach Scientific Reports