L CARNITINE Genetix Nutrition Compounded Carnitine (L) Injection Empower Pharmacy L Carnitine Side Effects & Safety: A Complete Guide The Science of Good Health 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. What Is Carnitine and Why Is It Important? The Amino Company L Carnitine: Benefits, Side Effects, And Dosage, Per Dietitians