Any advice for fishy smell with L carnitine? Does Carnitine Cause Body Odor? Lume Deodorant Overview 2023 FSU iGEM Nutricost L Carnitine Tartrate Powder, 100g, 1g per serving Walmart.com 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. 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.