Amino Acid Extreme and L Carnitine Extra Strength Combo Most people use L Carnitine wrong. They take it alongside a high carb diet expecting it to burn fat. Biologically, thats almost impossible., L Carnitine is an amino acid derivative that transports Klaire Labs SFI Health L Carnitine Tartrate 500 mg Amino Acid Stabilized L Carnitine No Synthetic L Carnitine is an amino acid that plays a role in energy production, by helping transport fatty acids into the mitochondria. Mitochondria are tiny powerhouses within cells that make energy.