Carnitine Deficiency: What Is It, Causes, Symptoms, and More Osmosis PCOS Nutrition Center L Carnitine (120 Capsules) 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. PCOS Nutrition Center L Carnitine (120 Capsules) Benefits of L Carnitine for PCOS: Improve Insulin Resistance & Weight Loss L Carnitine: Benefits, Dosage, Side Effects, and Food Sources Dr. Rogers Centers.com