L Carnitine in the Treatment of Psychiatric and Neurological Manifestations: A Systematic Review In the double blind, placebo controlled, double crossover trial published in Prostaglandins, Leukotrienes & Essential Fatty Acids, boys diagnosed with ADHD were given acetyl L carnitine at 100 mg per kg of body weight per day, divided Acetyl L Carnitine aSquared Brands Acetyl L Carnitine, 500 mg, 120 Vegetarian Capsules