L Carnitine and Male Fertility: Is Supplementation Beneficial? Frontiers Antioxidant therapy for infertile couples: a comprehensive review of the current status and consideration of future prospects Acetyl l Carnitine Pure Prescriptions Acetyl L carnitine is a form of the amino acid L carnitine, which helps turn fat into energy and occurs in the body naturally. It is thought to help slow down the ageing process