L Carnitine Losing weight with L carnitine supplements. Yes or no? 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 I get asked so many questions about my pre workout combo, so here it is! I take Oxyshred + Acetyl L Carnitine. This combo gives me the energy I need to crush my workouts