IAMS PROACTIVE HEALTH Adult Healthy Dry Cat Food with Chicken, 16 Pounds Pet Supplies Plus Carnitine in the crosshairs: A fishy tale? Dr. Ronald Hoffman How Much L Carnitine Should I Take? A Guide The Science of Good Health L carnitine what it is, properties, effects on weight loss + opinions 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. 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