Development and Application of a UPLCMRMMS Method for Quantifying Trimethylamine, Trimethylamine N Oxide, and Related Metabolites in Individuals with and Without Metabolic Syndrome Can choline supplementation cause a fishy body odor? Consensus Get Rid of Fishy L Carnitine Smell: Essential Fixes Tonum 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. Dietary supplementation of l carnitine ameliorates metabolic syndrome independent of trimethylamine N oxide produced by gut microbes in high fat diet induced obese mice Food & Function (RSC Publishing) Carnitine Deficiency: What Is It, Causes, Symptoms, and More Osmosis