L Carnitine: Benefits, Side Effects, FAQ, Sources, and Dosage Did you know L carnitine, a vital amino acid, is naturally produced by your body and found in various foods? While acetyl L carnitine (ALCAR) can be a beneficial supplement for some, most people get Role of carnitine in disease Nutrition & Metabolism Springer Nature Link When to take L carnitine: Dosage, forms, and side effects L Carnitine: Benefits, Side Effects, And Dosage, Per Dietitians