L Carnitine Injection Products list Products Ceva Australia Subcutanous injection self administration South Tees Hospitals NHS Foundation Trust 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 Subcutanous injection self administration South Tees Hospitals NHS Foundation Trust L Carnitine Linus Pauling Institute Oregon State University Subcutaneous Injection Sites and Instructions for Safe Self Administration