Carnitine: the claims and why it may not work Pictures of Things That Can Affect the Smell of Your Pee Why Does Asparagus Make Your Pee Smell? Find Out Here! 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 Amazon.com: Ronnie Coleman Signature Series L Carnitine XS 3000 Liquid, Amino Acids Metabolism and Lean Muscle Strength Support, Stimulant Free, Sugar Free, Zero Carbs, Grape, 16 Oz : Health & Household