[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Nursing](https://durgical.com/en/nursing/) › [Medications and dose calculation](https://durgical.com/en/nursing/areas/medication/) › Intramuscular injection: sites and technique # Intramuscular injection: sites and technique - Procedure An intramuscular injection places the drug in a muscle; the site is found with bony landmarks so nerves and vessels are not injured. Updated Nov 5, 2026 ## Key points - Sites: ventrogluteal (preferred in adults), deltoid (vaccines) and vastus lateralis (infants). - Avoid the dorsogluteal site: risk of sciatic nerve injury. - 90° angle, with a quick, firm motion; inject slowly. - Do not aspirate when giving vaccines (CDC); for other drugs, follow the institutional protocol. - Z-track: pull the skin aside before inserting, hold it during the injection and release it after withdrawing the needle, to seal the track. - The deltoid takes only a small volume; the maximum volume per site is set by the institutional protocol. On this page - The basics Key points - What it is - Indications - Equipment - Step by step (and why) - Next step: when to call for help - Elsewhere in DurgiPedia - Clinical Complications - Safety Contraindications and precautions - Study Test yourself - Connections Connections ## What it is The intramuscular (IM) route delivers the drug into muscle. The site is located with anatomical landmarks, not by eye. The ventrogluteal site is preferred in adults because it has thick muscle and no large nerves or vessels, and it is the site of choice for oily or irritating drugs; the deltoid is the usual site for vaccines in older children and adults; the vastus lateralis of the thigh is preferred in infants. The dorsogluteal site is avoided because of the risk to the sciatic nerve. The needle goes in at 90°. Vaccines are not aspirated. ## Indications - Vaccines and drugs ordered intramuscularly. - Oily or irritating drugs (the ventrogluteal site is preferred for them). ## Contraindications and precautions - Do not inject into skin with pain, infection, abrasions or necrosis. - Atrophied muscle absorbs the drug poorly; older adults and thin patients tolerate a smaller volume per injection. - Choose the needle length for the patient's size and the site. - Rotate sites when injections are repeated. ## Equipment - Prepared medication and medical order. - A syringe of the right size and a safety needle (gauge and length chosen for the patient and the drug). - Alcohol swabs and sterile gauze. - Clean gloves. - Sharps container. ## Step by step (and why) - Apply the rights and identify the patient — prevents wrong-drug and wrong-patient errors. - Choose the site and find it with bony landmarks (a V for the ventrogluteal) — keeps the needle away from nerves and vessels. - Clean the skin in circles outward and let the alcohol dry — reduces infection and stinging. - For Z-track, pull the skin aside with the non-dominant hand — seals the track on release. - Insert the needle at 90° with a quick motion — reaches the muscle with less pain. - Do not aspirate for a vaccine; for other drugs follow the protocol — the evidence does not support aspirating for vaccines. - Inject slowly; with Z-track, wait about ten seconds; withdraw smoothly at the same angle — reduces pain and leakage. - Release the skin, press with gauze without massaging and engage the needle's safety device — prevents leakage and needlesticks. - Discard the needle in the sharps container and document site, time and response — allows site rotation and monitoring. ## Complications - Pain, induration or local inflammation at the site. - Sciatic nerve injury at the dorsogluteal site, with partial or permanent paralysis of the leg. - Poor absorption in atrophied muscle. - Allergic reaction, including anaphylaxis. - Tissue hypertrophy from repeated injections at the same site. ## Next step: when to call for help - If blood appears in the syringe on aspiration: withdraw the needle, discard the preparation and prepare a new one. - Severe pain shooting down the leg or arm during the injection: stop and report. - Hives, difficulty breathing or facial swelling: activate the emergency response and report at once. - Redness, warmth or discharge at the site in the following days: report for medical review. ## Test yourself Think of the answer, then tap the question to see it. ## Which intramuscular site is preferred in infants? The vastus lateralis of the thigh (anterolateral thigh). ## Why is the dorsogluteal site avoided? Because of the risk of injuring the sciatic nerve, which can cause partial or permanent paralysis of the leg. ## Is aspiration done before an intramuscular vaccine? No. According to the CDC it is not needed, because the recommended sites have no large vessels, and it may be more painful for infants. ## What is the Z-track technique for? Pulling the skin aside before inserting and releasing it after the needle is withdrawn seals the track, so the drug does not leak into subcutaneous tissue. [Add to my cards (4)](https://durgical.app/estudiar/?add=/en/nursing/intramuscular-injection-sites-and-technique/) ## Elsewhere in DurgiPedia - [Colombia's PAI schedule (which vaccines, at what age)](https://durgical.com/en/immunology/colombia-s-pai-schedule/) ## Connections ## Related 3 - [Preparing parenteral medication: ampoules, vials and reconstitution](https://durgical.com/en/nursing/preparing-parenteral-medication-ampoules-vials-and-reconstitution/) - [Subcutaneous injection](https://durgical.com/en/nursing/subcutaneous-injection/) - [Intradermal injection](https://durgical.com/en/nursing/intradermal-injection/) [← All of nursing](https://durgical.com/en/nursing/) Educational content for students; it does not replace your institution's protocols, supervised clinical training or a prescriber's order. Dose-calculation examples use made-up numbers: they are educational, not a clinical order. Sources: [Nursing Skills (Open RN), 18.6 Administering Intramuscular Medications](https://med.libretexts.org/Bookshelves/Nursing/Nursing_Skills_(OpenRN)/18%3A_Administration_of_Parenteral_Medications/18.06%3A_Administering_Intramuscular_Medications) (Open RN, Chippewa Valley Technical College (LibreTexts), 2022); [Nursing Skills (Open RN), 18.3 Evidence-Based Practices for Injections](https://med.libretexts.org/Bookshelves/Nursing/Nursing_Skills_(OpenRN)/18%3A_Administration_of_Parenteral_Medications/18.03%3A_Evidence-Based_Practices_for_Injections) (Open RN, Chippewa Valley Technical College (LibreTexts), 2022); [Nursing Skills (Open RN), 18.8 Checklists for Parenteral Medication Administration](https://med.libretexts.org/Bookshelves/Nursing/Nursing_Skills_(OpenRN)/18%3A_Administration_of_Parenteral_Medications/18.08%3A_Checklists_for_Parenteral_Medication_Administration) (Open RN, Chippewa Valley Technical College (LibreTexts), 2022); [Vaccine Administration (General Best Practice Guidelines for Immunization)](https://www.cdc.gov/vaccines/hcp/acip-recs/general-recs/administration.html) (Centers for Disease Control and Prevention (CDC), 2024). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/nursing/intramuscular-injection-sites-and-technique/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/nursing/intramuscular-injection-sites-and-technique/