Creatine & Acetyl L Carnitine Energy Plus, 0.51 lb 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 Know About L Carnitine Injections for Weight Loss L Carnitine for Fat Burning: How It Really Works (Without the Hype) Is L Carnitine the Key to Fat Loss? Protyze From brain to muscle, L Carnitine plays a key role in energy metabolism, endurance, and recovery by supporting efficient fat to energy conversion.