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 Trimethylaminuria: Definition, symptoms, and more Did You Know? Some people report a fishy smell after supplementing with L carnitine. This happens because certain gut bacteria convert carnitine to trimethylamine, a malodorous compound found in rotting fish. Propionyl L carnitine for erectile dysfunction L Carnitine: Does It Really Help With Fat Loss? Supplement Store Lebanon Best Supplements in Beirut Scitec Nutrition Lebanon