L carnitine: Health Benefits, Side Effects, Uses, Dose & Precautions 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. Acetyl L Carnitine 500 mg ALCAR Amino Acid Supplement Vegan Capsul MOTHER NATURE SUPPLEMENTS L Carnitine: Benefits, Side Effects, And Dosage, Per Dietitians