Learn Fat Burner vs Pre Workout Differences and Selection Guide Can You Take L Carnitine With Pre Workout Nutrex Liquid L Carnitine 3000 Lunar Pop 31 Servings Combining L Carnitine with Pre Workout for Effective Fat Loss Taking a preworkout AND carnitine? It is important to get the timing of each supplement right to get the best results with both. Watch as Phil explains the best way to combine them. , #preworkout