Does L Carnitine Work for Fat Loss? A Dietitian Explains 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 L Carnitine: Benefits, Risks, and Its Role in Fitness and Weight Loss WellnessPulse L Carnitine: Everything You Need to Know Does Carnitine Cause Body Odor? Lume Deodorant Get Rid of Fishy L Carnitine Smell: Essential Fixes Tonum