Trimethylaminuria: Understanding and Treating Fish Odor Syndrome L Carnitine: Benefits, Uses, Side Effects, and More Govinda Lifecare Comparison of short term and long term effects of peroral L carnitine intake: clinical implications of elevated TMAO levels in cardiovascular complications 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. Comprehensive review of the expanding roles of the carnitine pool in metabolic physiology: beyond fatty acid oxidation Journal of Translational Medicine Springer Nature Link When to take L carnitine: Dosage, forms, and side effects