What Are the Best Intramuscular (IM) Injection Sites?

Intramuscular (IM) injections are shots delivered to a large muscle. They can be given by a healthcare provider or self-administered to the upper arm, thigh, buttock, or hip. IM injections are used for people of all ages, including infants.

Some IM injection sites may be preferred over others, depending on the age of the recipient, the type of medication used, the dose, the intramuscular needle size, and whether the shot is being given to yourself or by someone else. Choosing the right site is important as it helps reduce the risk of injury and ensures that the medicine is properly absorbed.

This article shows you how to find the four IM injection sites and provides instructions on how to give the shots safely. It also discusses the right injection technique as well as possible side effects. 

Where Are the Four IM Injection Sites?

There are four sites you can use to give yourself an IM shot. These sites have large, easy-to-locate muscles with little fatty tissue.

Upper Arm

Your deltoid muscle is the large muscle in your upper arm, just below your shoulder.

To find the injection site, feel for the bone at the top of your arm where your arm meets your shoulder. The injection site is about 2 inches below that spot (or roughly two or three finger widths). Be sure to give the injection in the center of the muscles where it is thickest.

It can be difficult to give yourself a shot in the deltoid muscle. You may need help from a partner.

Thigh

Your vastus lateralis and rectus femoris muscles are located in your thigh. They make up what is known as the quadriceps (quad) muscle. This is the easiest site for an IM injection if you are self-administering.

To find these muscles, imagine lines dividing the front of your thigh into thirds from the top to the bottom.

• To inject into the vastus lateralis, the needle should go into the middle third on the outer portion of your thigh.
• To inject into the rectus femoris muscle, the needle should go in the middle third at the front of your thigh.

Buttock

The dorsogluteal muscle is the large muscle located in your buttocks. It is one of the largest muscles on the body but can be awkward to access on your own. For this site, you will need a partner.

To find this site, divide one butt cheek into fourths from top to bottom and side to side. Your partner should give the injection in the outer, upper quadrant toward the hip. This is the part of the buttocks with the least fatty tissue.

Hip

Your ventrogluteal muscle is located near your hip. While it is possible to give yourself a shot there, it may be easier to do with a partner.

To find the site, lie on your back and have your partner stand facing your hips. Have your partner place the heel of their hand so that their wrist is lined up with your thigh.

Your partner's thumb should be pointed toward your groin and their fingers should be pointed toward your head. They should be able to feel the border of a bony area with their ring finger and pinkie.

Next, your partner should spread their pointer finger and middle finger into a "V" and give the injection between those fingers.

Proper Technique for IM Injections

Your healthcare provider will give you a prescription for your IM medication as well as for the appropriately sized syringes and needles. The gauge of the needle is especially important as small needles can fail if the injectable medication is thick.

A nurse or other healthcare provider will teach you or your partner how to deliver the injections. It is important that you are comfortable with the technique before doing it yourself.

If you are concerned about pain, you can numb the injection site for five to 10 minutes with ice. There are also numbing creams, typically containing lidocaine, available at most drugstores.

To give yourself or someone else an IM injection:

1. Gather your supplies: You will need a new needle and syringe, the medication vial, alcohol wipes, a sterile gauze pad, a cotton ball, and a bandage. You will also need a sharps container to dispose of the needle and syringe when you're done.
2. Wash your hands: Use soap and warm water and be sure to scrub under the nails and between the fingers.
3. Prepare the injection site: Spread the skin at the injection site between two fingers. Make sure the muscle is relaxed. Clean the injection site with an alcohol swab and let air dry.
4. Prepare the vial: If you're using a multi-dose vial, record the date when it was first used. Clean the rubber stopper with an alcohol swab.
5. Prepare the syringe: Remove the cap from the needle and draw air into the syringe equal to the size of the dose you will be injecting.
6. Draw up the medication: Push the needle through the rubber seal and inject the air into the vial. Turn the vial over so the rubber seal is on the bottom. Draw back the plunger to fill the syringe with the appropriate amount of medication. Withdraw the needle from the vial. Do not touch the needle.
7. Remove air from the syringe: Remove any air bubbles by gently tapping the syringe and compressing the plunger.
8. Give the injection: Hold the syringe firmly like a dart. The IM injection angle should be 90 degrees to the injection site. Insert the needle with a brisk, controlled motion (do not "stab" the needle). Compress the plunger slowly to inject the drug. Quickly remove the needle without changing the angle.
9. Apply light pressure: Press on the injection site with some gauze.
10. Discard the needle and syringe: Put them in a sharps container. Do not replace the cap on the needle. When the sharps container is full, dispose of it at an authorized collection center. Do not put syringes and needles or sharps containers into the trash.
    

Tips

Always ask your healthcare provider for clear instructions on how to give an IM injection. Don't be afraid to ask questions or request a repeat demonstration. Some of the most common questions about giving IM injections include:

Do You Pinch the Skin for an IM Injection?

Pinching the skin is not necessary when giving an intramuscular injection. Pinching the skin may cause you to deliver the injection into the subcutaneous layer instead of the muscle. Instead, use your non-dominant hand to slightly stretch the skin at the injection site.

How Deep Do You Insert a Needle for Intramuscular Injection?

Make sure the needle goes into the muscle to a depth of at least 1 inch.

Do You Pull Back When Giving an IM Injection?

Pulling back on the plunger before administering the injection is not necessary for most injections. Be sure to discuss this with your healthcare provider when they are showing you how to administer the injection.

Do You Rub After an IM Injection?

Your first instinct may be to massage an intramuscular injection site to ease the pain or help "get the medicine in," but doing so is not recommended. Massaging the injection site may force the medication from the muscle into the skin layers, reducing the absorption of the drug. It can also cause bruising.

Can You Hit the Bone With an Intramuscular Injection?

With the right size needle and proper injection site, the risk of hitting bone is unlikely. With that said, some muscles (like the deltoid muscle of the upper arm) are smaller in some people, and it is possible to hit bone if the shot is not given in the thickest part. Even so, it doesn't usually cause pain or complications.

How Can You Practice Giving an IM shot?

While you're getting the hang of it, you can practice by giving shots to an orange.

Possible Side Effects

There may be temporary pain and discomfort during the IM injection itself, but these tend to ease quite quickly. There also be minor bleeding, pain, swelling, or redness following the shot.

If you give yourself an injection in the dorsogluteal site, there is a risk of sciatic nerve injury. This can lead to a painful condition called sciatica that tends to resolve on its own but can make you uncomfortable for several days or weeks. Significant bleeding is also possible.

Although unlikely, it is possible to get an infection from an IM injection. This can occur if you do not adhere to hygienic practices (like washing your hands), reuse needles or syringes, or use medications that are expired or look tainted.

When Are IM Injections Given?

Self-administered IM injections may be used for different reasons, including assisted fertility treatments, gender-affirming hormone therapy, vitamin B12 supplementation, and some disease-modifying treatments for autoimmune diseases like rheumatoid arthritis.

If you're taking blood thinners or have a bleeding disorder or low platelet count, your healthcare provider may avoid intramuscular injections due to the risk of bleeding. They may also be inappropriate for people with hypovolemic shock or muscle wasting as these conditions will affect drug absorption.

Summary

There are four sites on your body that can be used to give yourself an intramuscular injection: the upper arm, thigh, hip, and buttocks. 

Make sure you are comfortable with the injection technique before you start giving yourself shots. A nurse or other healthcare provider can show you how to do it. Look out for side effects and report any concerns to your healthcare provider.