L Carnitine Is it Worth Taking? Ideal Nutrition (3 pack) Dr Teal's 3 in 1 Body & Hair Wash + Foaming Bath with Pure Epsom Salt, Performance with Menthol, L Carnitine & BCAAs, 34 fl oz. CUD Deficiency Primary Carnitine Deficiency Trimethylaminuria (Fish Odor Syndrome or TMAU) The Right Way to Take L Carnitine to Boost Your Training 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.