Does Carnitine Cause Body Odor? Lume Deodorant Potential Adverse Effects of L Carnitine Marnys The main reason some people may experience a fishy taste, smell, or burp when taking fish oil is that they are not taking a high quality #fishoil supplement. When it comes 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. Does Carnitine Cause Body Odor? Lume Deodorant PDF) [L carnitine treatment and fish odor syndrome: an unwaited adverse effect].