Understanding the Side Effects of L Carnitine Injection and When to Seek Medical Advice 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 Levocarnitine Injection: Package Insert Prescribing Info L Carnitine doesnt magically burn fat, it helps your body use fat as energy. Combine it with training and consistency, and youll feel the difference @Marybosch shows us how L Carnitine will boost