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 Erectile Dysfunction? Frontiers A mixture of postbiotics tyndallized probiotics reduces trimethylamine (TMA) in trimethylaminuria models: Evidence from in vitro and in vivo studies Stabilizing the enzyme in fish odor syndrome