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The content in Clinical Skills is evidence based and intended to be a guide to clinical practice. Always follow your organization’s practice.
ALERT
Intramuscular (IM) injections have been associated with adverse effects and pain, and this route of medication injection should be used as a last resort. Consider contacting the practitioner for an alternative, preferred route of medication administration.
Take extra care with a patient who takes medications that increase the risk for bleeding.undefined#ref4">4
Take steps to avoid interruptions and distractions when getting medications ready.
OVERVIEW
The IM injection route deposits medication into deep muscle tissue, which has a rich blood supply, allowing medication to be absorbed faster than it would be by the subcutaneous route. This rich blood supply, however, increases the risk for injecting drugs directly into blood vessels. Any factor that interferes with local tissue blood flow affects the rate and extent of drug absorption.
An IM injection may require a longer and larger-gauge needle to penetrate deep muscle tissue. The needle is inserted at a 90-degree angle; this varies from the angle used for subcutaneous and intradermal injections (Figure 1).2,5 The appropriate needle length is determined by the patient’s age and weight, injection site, and the amount of adipose tissue in the chosen injection site.2,7 The needle must be long enough to reach the muscle tissue but not too long to present the risk of hitting underlying neurovascular structures or bone.2
IM injections should be administered with the needle perpendicular to the patient’s body or as close to a 90-degree angle as possible.2,5 IM injection sites should be rotated to decrease the risk for hypertrophy. When possible, IM injections should not be administered in muscles that are emaciated or atrophied because they absorb medication poorly.5
Aspiration before injection and slow injection of the medication are not required for vaccine administration.2 The vastus lateralis and deltoid muscle are the only two sites recommended for vaccine administration because they do not contain large vessels that are within reach of the needle.2 For all other medications there is no evidence to support abandoning the practice of aspiration before administration. More research is needed to investigate the practice of aspiration before administering an IM injection with medications other than vaccines.9 The recommended route and site for each vaccine is included in the manufacturer’s instructions for use.10
Muscle tissue is less sensitive than subcutaneous tissue to irritating and viscous medications. Small muscles absorb small volumes. For a well-developed adult, no more than 3 ml of medication should be administered in a single IM injection because the muscle tissue does not absorb it well in larger volumes.5,8 For smaller adults or those with less muscle mass, the volume injected may need to be adjusted. There may be exceptions for specific medications. Refer to the organization’s formulary.
The Z-track method (pulling the skin laterally before injection) can be used if the overlying tissue can be displaced. This technique prevents medication leakage into subcutaneous tissue, seals medication in the muscle, and minimizes irritation.5 To use the Z-track method in an adult, the appropriate-size needle is attached to the syringe, and an IM site is selected. The overlying skin and subcutaneous tissues are pulled to the side with the ulnar side of the nondominant hand. The skin is held in this position until the injection has been administered. After the site is cleansed, the needle is injected deep into the muscle, and the medication is injected slowly. After the needle is withdrawn, the skin is released. The displacement of the skin and muscle layer closes off the needle track when the skin is released (Figure 2). The Z-track method should not be used with infant vaccinations where skin is compressed.
Injection Sites
For IM injections, the nurse selects a site that is free of pain, infection, necrosis, bruising, and abrasions. The location of underlying bones, nerves, and blood vessels and the volume of medication to be administered are also considered. Because of the sciatic nerve location, the dorsogluteal muscle is not recommended as an injection site. If a needle hits the sciatic nerve, the patient may experience partial or permanent paralysis of the leg.5,8 The rectus femoris is no longer considered a safe injection site because of the risk of damage to the descending branch of the lateral circumflex femoral artery and the muscle branch of the femoral nerve to the vastus lateralis.6
Ventrogluteal Site
The ventrogluteal site involves the gluteus medius and minimus muscles and is a safe injection site for adults, children, and infants.5 This site provides the greatest thickness of gluteal muscle that is free of penetrating nerves and blood vessels and it has a narrower layer of fat.5,8 The ventrogluteal site should be used with caution in infants.1 It is recommended that only an experienced pediatric health care team member use this site.
To locate the ventrogluteal site, the heel of the hand is placed over the greater trochanter of the patient’s hip with the wrist almost perpendicular to the femur. The right hand is used for the left hip, and the left hand is used for the right hip. The thumb is pointed toward the patient’s groin, with the index finger pointing to the anterior superior iliac spine, and the middle finger is extended back along the iliac crest toward the patient’s buttock. The index finger, the middle finger, and the iliac crest form a V-shaped triangle, with the injection site at the center of it (Figure 3). To relax this muscle site, the patient should lie flat and supine and flex the knee and hip, or the patient may lie on the side.
Vastus Lateralis Site
The vastus lateralis muscle is another injection site used in adults, children, and infants.5 The muscle is thick and well developed, and it is located on the anterior lateral aspect of the thigh. In an adult, the vastus lateralis extends from just above the knee to just below the greater trochanter of the femur (Figure 4). The middle third of the muscle is used for the IM injection site. To help relax this muscle site, the patient should lie flat, supine, flex the knee slightly, and externally rotate the foot, or the patient may assume a sitting position.
Deltoid Site
The deltoid site is easily accessible in many adults, but the muscle tends to be underdeveloped, which causes a potential for injury because the axillary, radial, brachial, and ulnar nerves and the brachial artery lie within the upper arm (Figure 5). This site can be used for small medication volumes (2 ml or less)5,8 and for administration of routine immunizations in children older than 3 years2,5 and adults with acceptable muscle mass and development, and when other sites are inaccessible because of dressings or casts.2
The deltoid muscle is located by fully exposing the patient’s upper arm and shoulder and asking the patient to relax the arm at the side or by supporting the patient’s arm and flexing the elbow. The lower edge of the acromion process, which forms the base of a triangle in line with the midpoint of the lateral aspect of the upper arm, is palpated, and the injection site is found in the center of the triangle (Figure 5).
To avoid shoulder injury related to vaccine administration, the nurse should always sit to inject into the arm of a seated patient to ensure that the angle of the needle is correct. If the patient’s shirt cannot be removed, the sleeve should be rolled up, so that landmarks can be visualized and used appropriately.4
Rarely, an adverse reaction occurs after immunizations. Reactions may include anaphylaxis, anaphylactic shock, and neurologic deficits.10 Vaccine adverse event reporting is monitored by the Centers for Disease Control and Prevention.
If the patient expresses worry about the accuracy of a medication, the medication should not be given. The concern should be explored, the practitioner notified, and the order verified.
SUPPLIES
See Supplies tab at the top of the page.
EDUCATION
Give developmentally and culturally appropriate education based on the desire for knowledge, readiness to learn, preferred learning style, and overall neurologic and psychosocial state.
Explain the procedure for an IM injection, including the purpose of the injection and the reason for using the IM route.
Explain the risks related to the procedure, including hematoma formation, nerve injury, and allergic reaction to the medication.
Teach the patient about the potential side effects of the medication.
If the patient requires regular injections, teach the patient on injection techniques and the importance of rotating sites to decrease the risk for hypertrophy.5
If regular injections are required, have the patient return demonstrate medication preparation to validate learning.
Teach the patient to observe the injection site for complications and provide instructions on the appropriate action to take if complications are observed.
Teach the patient to observe for effectiveness of the medication and adverse reactions.
Teach the patient to bring an up-to-date list of medications (over-the-counter, supplements, and prescriptions) to every practitioner visit.4
Encourage questions and answer them as they arise.
PROCEDURE
Clean hands and don appropriate personal protective equipment (PPE) based on the risk of exposure to bodily fluids or infection precautions.
Introduce yourself to the patient.
Verify the correct patient using two identifiers.
Explain the procedure and ensure that the patient agrees to treatment.
Ensure that evaluation findings are communicated to the clinical team leader.
Determine if the patient has specific contraindications to receiving an IM injection and notify the practitioner as needed. Evaluate for factors such as muscle atrophy, reduced blood flow, compromised skin condition, and circulatory shock.
Determine the patient’s current symptoms (if applicable) before initiating medication therapy to evaluate medication effectiveness after administration.
Determine the patient’s knowledge regarding the medication to be received.
Ask the patient about a history of allergies, including any drug allergies, type of allergens, and normal allergic reaction.
Review the patient’s previous verbal and nonverbal responses to injections.
Check accuracy and completeness of the practitioner’s original order.
Get the medication, check against the practitioner’s order, verify the expiration date, and check that the medication and container are clean and intact.
Do not use medication that is cloudy or precipitated unless such is indicated by its manufacturer as being safe.
Review medication reference information pertinent to the medication’s action, purpose, onset of action and peak action, normal dose, and common side effects and implications.
Check the rights of medication safety.
Label all medications and solutions. The only exceptions are medications that are still in their original container or medications that are given immediately by the person who prepared them.4
Medications or other solutions in unlabeled containers are unidentifiable. Errors, sometimes tragic, have resulted from medications and other solutions removed from their original containers and placed into unlabeled containers. This unsafe practice neglects basic principles of medication management safety, yet has been routine in many organizations.4
Assemble the appropriate-size needles, syringes, and other administration supplies, as needed.
Select the appropriate site for injection based on the patient’s age, weight, muscle tissue mass, and medication volume and viscosity.
Assist the patient to a comfortable position that is appropriate for the chosen injection site (e.g., sitting, or lying flat, on side, or prone).
Rationale: A comfortable position reduces strain on the muscle and minimizes injection discomfort.
Ensure that the patient’s injection site is accessible. If necessary, assist the patient with removing clothing.
Inspect the skin surface over sites for bruises, inflammation, or edema.
Rationale: Injection sites should be free of abnormalities that interfere with drug absorption (e.g., bruising, signs associated with infection).
Note the integrity and size of the muscle. Palpate for tenderness or hardness and avoid hardened areas. If the patient receives frequent injections, rotate sites.
Rationale: Sites used repeatedly become hardened from lipohypertrophy (increased growth in fatty tissue).
Locate the injection site again using anatomic landmarks. The ventrogluteal site is a safe injection site for adults and children receiving irritating or viscous solutions and is the site of choice for administering IM injections to adults.5,8 In addition, this site provides the greatest thickness of gluteal muscle, is free of penetrating nerves and blood vessels, and has a narrower layer of fat.5,8
Rationale: Injection into the correct anatomic site prevents injury to nerves, bone, and blood vessels.
The dorsogluteal site is not recommended because of proximity to the sciatic nerve.5,8
Clean the site with alcohol or an antiseptic swab. Allow the skin to dry completely. Optional: Use a vapocoolant spray (e.g., ethyl chloride) for pain relief just before injection.
Rationale: A vapocoolant spray decreases pain at the injection site.
Hold a clean swab or dry gauze between the third and fourth fingers of the nondominant hand.
Rationale: The swab or gauze remains readily accessible for use when withdrawing the needle.
Remove the needle cap by pulling it straight off.
Rationale: Pulling the cap straight off prevents the needle from touching the sides of the cap, thus preventing contamination.
Hold the syringe between the thumb and forefinger of the dominant hand as if holding a dart, palm down.
Rationale: A quick, smooth injection requires proper manipulation of the syringe parts.
With your nondominant hand, pull the skin taut.
Administer the injection using the Z-track method, if appropriate.
Position the ulnar side of the nondominant hand just below the site and pull the skin laterally. Hold this position until the medication is injected.
With the dominant hand, inject the needle quickly into the muscle at a 90-degree angle using a steady and smooth motion.5,8
Rationale: The Z-track technique creates a zigzag path through tissues that seals the needle track to avoid tracking medication. A quick, dart-like injection reduces discomfort. Z-track injections may be used for all IM injections.5,8
After the needle pierces the skin, use the thumb and forefinger of the nondominant hand to hold the syringe barrel while still pulling on the skin. Move the dominant hand to the end of the plunger. Avoid moving the syringe.
Rationale: Smooth manipulation of the syringe reduces discomfort from needle movement. Skin remains pulled until after the medication is injected to ensure Z-track administration.
Optional: If the patient’s muscle mass is small, grasp the body of the muscle between the thumb and forefingers of the nondominant hand while still pulling the skin laterally.
Rationale: Grasping the muscle body helps ensure that the medication reaches the muscle mass.
Per the organization’s practice, pull back on the plunger. If no blood appears, inject the medication. If blood appears in the syringe, remove the needle, discard the medication, obtain a new syringe, and try again.
Rationale: Aspiration of blood into the syringe indicates possible placement into a vein.
Rationale: There is no definitive research to recommend eliminating aspiration other than for vaccination and toxoids.5,8
Smoothly, quickly, and steadily withdraw the needle and release the skin. Apply a dry cotton ball or gauze with light pressure for several seconds over the site.
If not using the Z-track method, follow these steps for injection.
With the dominant hand, inject the needle quickly into the muscle at a 90-degree angle using a steady and smooth motion.5,8
After the needle pierces the skin, use the thumb and forefinger of the nondominant hand to hold the syringe barrel while still pulling on the skin. Move the dominant hand to the end of the plunger. Avoid moving the syringe.
Optional: If the patient’s muscle mass is small, grasp the body of the muscle between the thumb and forefingers of the nondominant hand.
Rationale: Grasping the muscle body helps to ensure that the medication reaches the muscle mass.
Per the organization’s practice, pull back on the plunger. If no blood appears, inject the medication. If blood appears in the syringe, remove the needle, discard the medication, obtain a new syringe, and try again.
Rationale: Aspiration of blood into the syringe indicates possible placement into a vein.
Rationale: There is no definitive research to recommend eliminating aspiration other than for vaccination and toxoids.5,8
Smoothly, quickly, and steadily withdraw the needle. Apply a dry cotton ball or gauze with light pressure for several seconds over the site.
Apply gentle pressure to the site; do not massage. Evaluate the site and apply a bandage if needed.
Rationale: Massage damages underlying tissue.
Replace the patient’s clothing and assist the patient to a comfortable position.
Discard the uncapped needle (or needle enclosed in the safety shield) and attached syringe into a puncture-proof and leakproof receptacle.
Rationale: Discarding the uncapped needle helps prevent injury to the patient and health care team members. Recapping needles increases the risk for a needlestick injury.7
Watch the patient for adverse and allergic reactions to the medication. If a reaction occurs, follow the organization’s practice for emergency response.
Discard supplies, remove PPE, and clean hands.
Document the procedure in the patient’s record.
EXPECTED OUTCOMES
Medication administered according to the rights of medication safety
Desired effect of medication with no adverse reactions, signs of allergies, or undesired effects
Acceptable level of comfort after injection
Patient able to explain purpose, dose, and effects of medication
UNEXPECTED OUTCOMES
Medication not administered according to the rights of medication safety
Patient complaints of localized pain, bleeding, or continued burning at injection site, indicating potential injury to nerve or vessels
Blood aspiration during injection
Medication administration in subcutaneous tissue
Adverse reaction to the medication, with signs of urticaria, eczema, pruritus, wheezing, or dyspnea
Other adverse effects: hematoma or abscess; infection; fibrosis of the muscle, tissue damage because of patient movement during injection; glass particles injected into muscle as a result of not using a filter needle; permanent damage to sciatic nerve resulting in paralysis, fibrosis, or abscess
Unmanaged pain
DOCUMENTATION
Medication name, dose, route, site, time, and date of administration
Patient’s response to medication, including any adverse reactions
Unexpected outcomes and related interventions
Education
Patient’s comfort and interventions performed
Patient’s weight in kilograms
Evaluation findings communicated to the clinical team leader per the organization’s practice
PEDIATRIC CONSIDERATIONS
Children can be very anxious or fearful of needles. Assistance is sometimes necessary to hold and properly position the child. Distraction, such as blowing bubbles and applying pressure at the injection site before administering the injection, may help alleviate the child’s anxiety.
If possible, a topical analgesic should be applied to the injection site with sufficient time allowed for peak action before the IM injection. A vapocoolant spray (e.g., ethyl chloride) may also be used just before the injection to decrease pain.
The vastus lateralis muscle is the preferred site for administration of immunizations to newborns, infants, and children up to 3 years old.2 The deltoid muscle is the acceptable site for administration of routine immunizations in children 3 to 18 years old who have acceptable muscle mass and development.2,5
Applying a colorful adhesive bandage or sticker to the injection site should be considered.
OLDER ADULT CONSIDERATIONS
Older adult patients may have decreased muscle mass, which reduces drug absorption from IM injections.
Older adult patients may have loss of muscle tone and strength that impairs mobility, placing them at high risk for falls as a result of guarding an injection site.
Older adult patients who require frequent injections should be instructed to apply a topical analgesic to the injection site before administration.
Anderson, C.E., Herring, R.A. (2022). Chapter 20: Pediatric nursing interventions and skills. In M.J. Hockenberry, C.C. Rodgers, D. Wilson (Eds.), Wong’s essentials of pediatric nursing (11th ed., pp. 551-618). St. Louis: Elsevier.
Institute for Safe Medication Practices (ISMP). (2024). 2024-2025 Targeted medication safety best practices for hospitals. Retrieved May 31, 2024, from https://www.ismp.org/guidelines/best-practices-hospitals
Lilley, L.L., Rainforth Collins, S., Snyder, J.S. (2023). Chapter 9: Photo atlas of drug administration. In Pharmacology and the nursing process (10th ed., pp. 102-134). St. Louis: Elsevier.
Nakajima, Y. and others. (2020). Anatomically safe sites for intramuscular injections: A cross-sectional study on young adults and cadavers with a focus on the thigh. Human Vaccines and Immunotherapeutics, 16(1), 181-196. doi:10.1080/21645515.2019.1646576
Reed, A.E. (2025). Chapter 22: Parenteral medications. In A.G. Perry and others (Eds.), Clinical nursing skills & techniques (11th ed., pp. 659-716). St. Louis: Elsevier.
Sepah, Y. and others. (2017). Aspiration in injections: Should we continue or abandon the practice? (version 3, peer review, 2 approved). F1000Research, 3, 157. doi:10.12688/f1000research.1113.3
Wodi, A.P., Shimabukuro, T. (2021). Chapter 4: Vaccine safety. In E. Hall and others (Eds.), Epidemiology and prevention of vaccine-preventable diseases (14th ed., pp. 43-52). Centers for Disease Control and Prevention (CDC). Washington, DC: Public Health Foundation. Retrieved May 31, 2024, from https://www.cdc.gov/vaccines/pubs/pinkbook/safety.html
U.S. Food and Drug Administration (FDA). (2021). Safely using sharps (needles and syringes) at home, at work and on travel. Retrieved May 31, 2024, from
