L Carnitine Injections: A Clinical Guide for Practitioners National Medical Resources Inc Injectable L Carnitine for Slimming: Does It Really Work? National Medical Resources Inc Are some methods of administering HRT inherently better than others? Audience requested: subcutaneous injections. Subcutaneous means under the skin. In this type of injection, a short needle is used to inject medication 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