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 Subcutaneous Injection: What It Is and How to Give One L Carnitine Injectable Factor Health MD Compounded Carnitine (L) Injection Empower Pharmacy Where to Inject L Carnitine for Maximum Fat Loss Benefits How To Give a Subcutaneous (SubQ or SQ) Injection OncoLink