L Carnitine for Weight Loss: How It Works, Dosage & Best Supplement Zeelab Pharmacy Pharmacokinetics of L Carnitine : Clinical Pharmacokinetics A fishy tasting steak is an indicator that your beef is old. As meat breaks down, it can release TMA, a compound responsible for unpleasant, fishy flavors. 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 5000