Revisiting the Role of Carnitine in Heart Disease Through the Lens of the Gut Microbiota Amazon.com: Benevolent L Carnitine Supplement High Potency 1500mg L Carnitine Tartrate Fast Absorbing, Convert Fat to Energy, Support Lean Muscle, Boost Workout Performance & Metabolism 120 Vegan Capsules : Health & Household 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: Nutricost Acetyl L Carnitine (ALCAR) 500mg, 180 Capsules, 180 Servings Non GMO and Gluten Free, 1 Capsule per Serving : Everything Else