Any advice for fishy smell with L carnitine? 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. When a 12 month old boy in Portugal developed an unexpected and persistent smell similar to rotting fish, his parents were unsettled. The child appeared healthy, showed no signs of infection, and behaved normally. L Carnitine Promix Nutrition L Carnitine Warning Smelly Sweat : r moreplatesmoredates Fish Odor Syndrome Springer Nature Link