Acetyl L Carnitine: Benefits and Side Effects Gene Food 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 Understanding the Side Effects of L Carnitine Injection and When to Seek Medical Advice L Carnitine Injections: Before and After Results Stabilizing the enzyme in fish odor syndrome