Effects of Oral L Carnitine Administration in Narcolepsy Patients: A Randomized, Double Blind, Cross Over and Placebo Controlled Trial PLOS One Acetyl L Carnitine for Heart, Diabetes & Kidney Health Kidney Coach Most energy drinks are loaded with caffeine and sugar, which can cause jitters, dehydration, headaches, and even affect your heart if consumed often. While an occasional drink may not cause harm, regular L Carnitine Benefits, Uses, Dosage, Foods, Side Effects Dr. Axe