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 Emrald Labs Acetyl L Carnitine Carnitine Supplements Review Acetyl L Carnitine: Benefits and Side Effects Gene Food Confident Sports L Carnitine Confident Health Understanding the Benefits and Uses of Carnitine in Health and Fitness Fitness Health L carnitine is a naturally occurring amino acid structure that is made in the human brain, liver, and kidneys. L carnitine plays a critical role in energy production, as it converts fat into energy.