L Carnitine vs Acetyl L Carnitine: Which is Better Metabolism: Master the Carnitine Shuttle and Stop Exam Stress! Long Chain Fatty Acids (LCFAs) love to burn energy, but they face a major obstacle: they cannot enter the mitochondrial matrix where Beta Oxidation From increased energy to better sleep and improved brain function, this amino acid can tackle a lot. Because acetyl L carnitine can pass through the semi permeable membrane around your brainthe blood brain barrier ( Creatine VS L Carnitine