The Role of l Carnitine in Mitochondria, Prevention of Metabolic Inflexibility and Disease Initiation 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 Frontiers A mixture of postbiotics tyndallized probiotics reduces trimethylamine (TMA) in trimethylaminuria models: Evidence from in vitro and in vivo studies Product Spotlight: L Carnitine Coastal Pharmacy & Wellness