An intramuscular (IM) injection is a shot. The needle goes into the muscle to deliver medicine. This is usually done by a doctor or nurse. Sometimes, your doctor may teach you to inject yourself. IM injections are deeper than subcutaneous injections (given under the skin).

Intramuscular Injection

intramuscular injection
A needle passes through skin and fat layers into the muscle fibers to deliver medicine.
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Reasons for Procedure

Some medicines are better absorbed when given in the muscle; if taken by mouth, they may not work. Other medicines may be given in the muscle if you are unable to take them by mouth.

Some examples of medicines given using an IM injection:

Possible Complications

Complications associated with IM injections are:

  • You may have some bleeding, soreness, or redness at the site.
  • Allergic reaction to the medicine is possible. If you may be allergic to a medicine, do not inject it.
  • Rarely, the site may become infected.

What to Expect

Prior to Procedure

  • Make sure you have all of the items that you will need (eg, syringe, medicine, and cleaning materials).
  • Make sure that you have the right medicine and that it has not expired.
  • Wash hands with warm, soapy water before giving the injection.
  • Select a site for injection. This should be an area on your body with a large muscle (eg, thigh).
  • Cleanse the area with an alcohol wipe.

Description of Procedure

To inject yourself:

  • Remove the needle cap.
  • Smooth the skin with one hand.
  • Hold the syringe the way you would a pencil. Insert the needle at a 90° angle to the skin. (The needle should be completely covered by skin).
  • Hold the syringe with one hand. With the other, pull back the plunger to check for blood in the syringe.
    • If you see blood, do not inject. Withdraw the needle and start again at a new site.
    • If you do not see blood, slowly press down on the plunger until it stops.
  • Remove the needle from the skin.
  • If there is bleeding at the site of injection, apply a bandage.
  • Immediately put the syringe and needle into a container that is puncture-proof.
  • Find out what services are available in your area for disposing of biological waste.

Will It Hurt?

Depending on the medicine, there is usually some discomfort at the injection site. Soreness in the muscle is also common.

Tips for minimizing pain include:

  • Inject medicine that is at room temperature.
  • Remove all air bubbles from the syringe before the injection.
  • Relax the muscles in the injection area.
  • Quickly break through the skin.
  • Do not change the direction of the needle as it goes in or comes out.
  • Do not reuse disposable needles.

Care After Injection

Follow your doctor's instructions for general care.

Call Your Doctor

Contact your doctor if any of the following occurs:

  • Difficulty giving yourself the injection
  • Continued bleeding at the injection site
  • A lot of pain
  • Medicine is injected into the wrong area
  • Rash or swelling at the injection site
  • Fever or allergic reaction develops

In case of an emergency, call 911.