Subcutaneous injection

A subcutaneous injection or shot is one into the fatty tissues just beneath the skin. These injections are shallower than those injected into muscle tissues.

Providers often use subcutaneous injections for medications that must be absorbed into the bloodstream slowly and steadily, such as insulin.

Subcutaneous injections are usually safe and do not require as much force as intramuscular injections into the muscle tissues.

The subcutaneous injection can be used to give many types of medications for various medical conditions.

There are fewer blood vessels in the fatty layer of connective tissue just beneath the skin than the muscle tissue.

Having fewer blood vessels means that medication injected subcutaneously is absorbed more slowly.

This makes it an ideal way to administer medications that the body must use slowly over time, such as insulin for the treatment of diabetes.

Medications given this way include:

  • insulin for diabetes
  • blood thinners, such as heparin
  • some fertility drugs
  • some drugs, such as Enbrel and Kineret, for autoimmune diseases, including arthritis
  • various peptides such as sermorelin, ipamorelin, and others

Many drugs that must be taken daily, or injected at home, are designed for subcutaneous injection.

How to do a subcutaneous injection

To give a subcutaneous injection, people should follow these steps:

  1. Choose a fatty area of the body, such as the abdomen, back of the arm, or thigh: If you are giving several injections or have to do daily injections, rotate the sites to allow each area to heal between injections
  2. Wash hands before cleaning the area with an alcohol pad: Wait for the area to completely dry before the next step.
  3. Take the cap off the needle: Draw the medication into the syringe, according to the directions on the vial. This usually means turning the vial upside down then pulling the plunger back to suck in the medication. Tap the syringe to get rid of air bubbles.
  4. Pinch a fold of skin: Pinch the fatty area about 2-inches thick in between the thumb and a finger.
  5. While holding the needle like a dart, slide it into the skin at an angle of 90 degrees: Needles used for subcutaneous injection are usually short and small and should go all the way into the skin.
  6. Push the plunger all the way down quickly: Do not push forcefully.
  7. Cover the needle: Dispose of the needle in a needle-safe container.

The best location for a subcutaneous injection depends on a person’s pain sensitivity and where they have some subcutaneous fat.

A few commonly chosen locations include:

  • the backs or sides of the arms
  • the fatty part of the stomach
  • the front of the thighs
  • the top of the buttocks, where there is more fat than muscle

Some subcutaneous injections come in the form of an auto-injector. An auto-injector is a self-contained device that does not require drawing the medication up first. People can follow the instructions on the package if they are using an auto-injector.