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. Chocolate boosts happiness by increasing serotonin, a neurotransmitter that regulates mood and promotes calmness, and endorphins, the body's natural painkillers that create a sense of euphoria and reduce stress. The Right Way to Take L Carnitine to Boost Your Training L Carnitine Side Effects & Safety: A Complete Guide The Science of Good Health