L Carnitine injection is recommended at 1 ampule every 2 3 days for best results. The L Carnitine is taken intravenously either by normal injection or using a butterfly needle. After taking this L Carnitine, you Effects of Oral L Carnitine Administration in Narcolepsy Patients: A Randomized, Double Blind, Cross Over and Placebo Controlled Trial PLOS One Effects of Oral L Carnitine Administration in Narcolepsy Patients: A Randomized, Double Blind, Cross Over and Placebo Controlled Trial PLOS One Role of carnitine in disease Nutrition & Metabolism Springer Nature Link Carnitine: the claims and why it may not work Insomnia, Cognitive Impairment, or a Combination of Both, Alter Lipid Metabolism Due to Changes in Acylcarnitine Concentration in Older Persons