Which of the following techniques is correct to give an intramuscular injection? A guide to safe practices.

September 30, 2025 •

5 min read

It is estimated that for every vaccine injected intramuscularly, 20 injections are administered for other therapies, highlighting the widespread use and importance of mastering the correct technique to give an intramuscular injection. Administering an IM injection properly is a critical skill for healthcare professionals and patients who self-administer certain medications.

Quick Summary

This guide details the steps for administering a safe and effective intramuscular injection, covering site selection, preparing the medication and patient, and using the recommended Z-track method. It also explains crucial safety considerations, including proper needle insertion and sharps disposal.

Key Points

Practice Z-Track Technique: Always pull the skin and subcutaneous tissue to the side before injecting to seal the medication within the muscle and prevent leakage.
Choose the Right Site: Select the most appropriate injection site—deltoid, ventrogluteal, or vastus lateralis—based on patient age, body mass, and medication volume.
Insert at a 90-Degree Angle: Ensure the needle enters the muscle at a 90-degree angle for a quick, accurate, and less painful injection.
Inject Slowly and Wait: Push the plunger slowly to minimize discomfort and wait 10 seconds after injecting to allow the medication to disperse before withdrawing the needle.
Never Massage the Site: After withdrawing the needle, apply gentle pressure with gauze, but avoid massaging the area, which can cause bruising and leakage.
Dispose of Sharps Safely: Immediately place the used needle and syringe into a designated sharps container to prevent accidental needle-stick injuries.

Preparation is Key

Before administering any intramuscular (IM) injection, meticulous preparation is essential to ensure safety and prevent infection. Proper preparation includes gathering the necessary supplies, understanding the patient's medical history, and ensuring the environment is sterile.

Gathering Supplies:

Medication vial or ampoule
Syringe and appropriate needle (length and gauge depend on the patient and site)
Alcohol wipes
Cotton balls or gauze
Adhesive bandage
Clean gloves
Sharps container for safe disposal

Preparing the Patient and Medication:

Patient Identification and Consent: Use two identifiers to confirm the correct patient. Explain the procedure and obtain consent.
Hand Hygiene and Gloves: Wash hands thoroughly with soap and water, and put on clean gloves.
Site Selection: Carefully assess the patient to select the most appropriate injection site. Avoid areas with infection, inflammation, or significant muscle atrophy.
Medication Preparation: Follow standard aseptic procedures when drawing up the medication. For glass vials, use a filter needle and change it before injecting. If using a safety needle, follow the manufacturer's instructions.

The Z-Track Technique: The Recommended Standard

For most intramuscular injections, the Z-track technique is the recommended standard of care. This method is crucial for preventing medication leakage into the subcutaneous tissue, minimizing irritation, and ensuring the medication stays sealed within the muscle.

To perform the Z-track technique:

Use the non-dominant hand to pull the skin and subcutaneous tissue laterally (to the side) by about 1 to 1.5 inches.
Hold the skin firmly in this displaced position throughout the injection.
After the injection, withdraw the needle and then release the skin. This creates a zigzag path that seals the medication deep within the muscle, preventing backflow.

The Correct Steps for Administering an Intramuscular Injection

The following steps outline the correct process for administering an IM injection, incorporating the Z-track technique:

Clean the Injection Site: Clean the skin with an alcohol swab, moving in a circular motion from the center outwards. Allow the site to air dry completely.
Position the Syringe: Hold the syringe like a dart in your dominant hand, keeping your fingers off the plunger.
Perform Z-Track: Use your non-dominant hand to pull the skin laterally.
Insert the Needle: Insert the needle into the muscle at a 90-degree angle with a quick, dart-like motion. The speed of insertion can reduce discomfort.
Aspirate (If Necessary): While routine aspiration is no longer recommended for most vaccines, some institutions and specific medications still require it. If instructed, pull back on the plunger for 5-10 seconds. If blood appears, withdraw and prepare a new injection at a different site.
Inject the Medication: Slowly and steadily push the plunger to inject the medication. Injecting slowly (e.g., 10 seconds per mL) allows the muscle fibers to accommodate the fluid, minimizing discomfort.
Wait and Withdraw: Wait for 10 seconds after the injection to allow the medication to disperse. Then, withdraw the needle at the same 90-degree angle, smoothly and steadily.
Release Skin and Apply Pressure: As you withdraw the needle, release the traction on the skin. Apply gentle pressure with a gauze pad but do not massage the site, as this can increase bruising and promote leakage.
Safe Sharps Disposal: Immediately activate the needle's safety device and dispose of the entire syringe into the sharps container.

Selecting the Correct Injection Site

Choosing the right site is crucial to avoid nerves and blood vessels. The most common and safest sites are the ventrogluteal, vastus lateralis, and deltoid muscles.


Injection Site	Max Volume	Common Patient Population	Key Considerations
Deltoid	up to 2 mL	Older children and adults	Easily accessible for vaccines, but small muscle mass limits volume. Located in the middle of the triangular muscle, 2-3 finger-widths below the acromion process. Avoid neurovascular bundles below.
Ventrogluteal	up to 3 mL	Adults and children older than 7 months	Considered the safest site due to the absence of major nerves and vessels. Locate by placing the heel of the hand on the greater trochanter, with the index finger on the anterior iliac spine, forming a 'V' shape for injection.
Vastus Lateralis	up to 5 mL	Infants and small children	Preferred site for neonates and infants, and a common site for self-administration. Located in the middle third of the anterolateral thigh.

Potential Complications of Improper Technique

Failure to use the correct intramuscular injection technique can lead to serious complications, including:

Nerve Damage: Injecting too close to a nerve (e.g., sciatic, radial, axillary) can cause severe pain, numbness, or paralysis.
Abscess Formation: An infection at the site can cause a painful, swollen lump, which may require medical intervention.
Vascular Injury: Hitting a blood vessel can cause a hematoma, pain, or if oil-based medication enters the bloodstream, a vascular occlusion.
Tissue Necrosis: Injecting certain substances improperly can lead to localized tissue death.
Infection Transmission: Using unsterilized equipment or improper aseptic technique can transmit infections like HIV or hepatitis.

Conclusion

For any healthcare provider or individual tasked with administering an intramuscular injection, adhering strictly to the correct technique is non-negotiable. Using the Z-track method, carefully selecting the injection site, and practicing meticulous aseptic technique are the correct steps to ensure patient safety, minimize discomfort, and prevent dangerous complications. Comprehensive training and a solid understanding of these principles are vital for successful and safe medication administration. For more in-depth guidance, resources from institutions like the Centers for Disease Control and Prevention (CDC) offer detailed information on vaccine administration techniques.

How to give an intramuscular injection

Wash hands and prepare the required equipment on a clean surface.
Draw up the correct dose of medication using aseptic technique.
Select a safe injection site, using anatomical landmarks for accuracy.
Clean the injection site with an alcohol wipe and allow it to dry completely.
Pull the skin and underlying tissue laterally using the Z-track technique.
Insert the needle at a 90-degree angle with a swift motion.
Inject the medication slowly and steadily.
Wait 10 seconds, then withdraw the needle at the same angle.
Release the skin and apply gentle pressure with gauze; do not massage.
Immediately dispose of the used needle and syringe in a sharps container.
Observe the patient for any adverse reactions for several minutes.

Frequently Asked Questions

Routine aspiration (pulling back on the plunger) is no longer recommended for most IM injections, especially vaccines, as it can cause more discomfort. However, specific institutional policies or medications may still require it, so always follow your provider's instructions.

The ventrogluteal site, located on the hip, is widely considered the safest site for IM injections because it is free of major nerves and blood vessels. It is the preferred site for adults and children over 7 months.

To locate the deltoid muscle, find the acromion process (the bony point at the shoulder's end). The injection site is approximately 2 to 3 finger-breadths (about 2 inches) below this bone, in the central, thickest part of the muscle.

The Z-track technique is used to prevent medication from leaking back into the subcutaneous tissue and to minimize irritation at the injection site. By displacing the skin before insertion and releasing it after withdrawal, a zigzag path is created that seals the medication within the muscle.

The buttock (specifically the dorsogluteal site) carries a higher risk of nerve injury, particularly to the sciatic nerve. While traditionally used, the ventrogluteal site on the hip is a safer alternative and is now the preferred method.

Needle size (length and gauge) depends on the patient's age, weight, and muscle mass, as well as the injection site. Heavier patients typically require longer needles, while infants and small children need shorter ones. Follow specific recommendations or consult with a healthcare provider.

Some localized pain, redness, or bruising is common after an IM injection and is typically mild. However, severe pain, swelling, or numbness could indicate a complication and should be reported to a healthcare provider.