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. Effect of dietary fiber on trimethylamine N oxide production after beef consumption and on gut microbiota: MEATMARK a randomized cross over study European Journal of Clinical Nutrition Does Carnitine Cause Body Odor? Lume Deodorant Carnitine metabolism to trimethylamine by an unusual Rieske type oxygenase from human microbiota PNAS L Carnitine Pills for Weight Loss: Evidence, Safety and UK Guidance Bolt Pharmacy Development and Application of a UPLCMRMMS Method for Quantifying Trimethylamine, Trimethylamine N Oxide, and Related Metabolites in Individuals with and Without Metabolic Syndrome