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 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 Lipo C Injection Empower Pharmacy Routes of Drug Administration Springer Nature Link