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 Infusions Injections with L Glutamina Quantica720 Intramuscular vs. Subcutaneous Injections: What's the Difference? Intramuscular (IM) shots go deep into the muscle for faster absorption, while subcutaneous (SubQ) injections are placed just under the skin for slower, more sustained LCarnitine Injections Energy & Fat Metabolism Support TX