L Carnitine 5000 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. Your urine's smell can reveal a lot about your health. A strong ammonia like odor could indicate kidney stress, while a fruity scent may suggest ketones. Sweet smelling urine might point to diabetes risk, 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. 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, Orange Smash, 16 Oz : Health & Household