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 Where to Inject L Carnitine for Maximum Fat Loss Benefits Subcutanous injection self administration South Tees Hospitals NHS Foundation Trust L Carnitine Injection HOMEKIT How to Give Yourself A Subcutaneous Injection