Intramuscular Injection: how to give it?

Marketing Dept., | 10 min read
Marketing Dept., | 10 min read

Intramuscular (IM) injections are a common and effective method for delivering medications, including antibiotics, hormones, and vaccinations, directly into the muscle tissue. This technique ensures that the medication is absorbed quickly into the bloodstream, providing rapid and efficient treatment. In this blog post, we will delve into the details of IM injections, their applications, and the proper techniques for administering them, based on insights from the JoVE video "Intramuscular Injection of Antibiotics, Hormones, and Vaccinations."

What is an Intramuscular Injection?

An intramuscular injection involves the administration of medication into a muscle. Muscles have a rich blood supply, allowing for faster absorption of the drug compared to subcutaneous or intradermal injections. Common sites for IM injections include the deltoid muscle in the arm, the vastus lateralis muscle in the thigh, and the gluteus medius muscle in the buttocks. 

  • Intramuscular Injection Examples and Applications

IM injections are used for a variety of medical purposes:

  1. Antibiotics: Administering antibiotics via IM injection can be crucial for treating severe infections, particularly when oral administration is not feasible.
  2. Hormones: Hormonal treatments, such as testosterone or estrogen therapy, often require IM injections to ensure proper absorption and efficacy.
  3. Vaccinations: Many vaccines, including those for influenza, hepatitis, and COVID-19, are delivered via IM injection to provoke a strong immune response.

How do you give Intramuscular Injections? Proper Technique 

Administering an intramuscular (IM) injection requires careful technique to ensure efficacy and minimize discomfort and complications. First, gather all necessary supplies, including the medication, syringe, needle, alcohol swabs, and gloves. Ensure the medication is at room temperature and check for any particulate matter or discoloration. Position the patient comfortably, ensuring the chosen muscle is relaxed for accessibility to the injection site. Select the appropriate injection site based on the patient's age, muscle mass, and the volume of medication, with common sites including the deltoid muscle for small volumes (up to 2 mL), the vastus lateralis muscle for infants and young children, and the gluteus medius muscle for larger volumes (up to 5 mL).

Clean the injection site with an alcohol swab using a circular motion from the center outward and allow the skin to dry. Hold the syringe like a dart and insert the needle at a 90-degree angle to the skin, quickly and firmly into the muscle. Before injecting the medication, gently pull back on the plunger to ensure the needle is not in a blood vessel; if blood appears, remove the needle and choose a new site. Slowly depress the plunger to inject the medication into the muscle. Withdraw the needle quickly and apply gentle pressure to the injection site with a clean cotton ball or gauze. Finally, dispose of the needle and syringe in a proper sharps container.

Post-Injection Care

After the injection, monitor the patient for any adverse reactions, such as pain, swelling, or redness at the injection site. Provide instructions for post-injection care, including:

  • Keeping the injection site clean and dry.
  • Avoiding strenuous activity that involves the injected muscle for 24 hours.
    • eporting any severe or persistent side effects to a healthcare provider.


      Choosing the Right Needle Length for Intramuscular Injections

      Administering intramuscular (IM) injections requires selecting the correct needle length to ensure the medication reaches the muscle tissue effectively. Here's a quick guide based on age, weight, and injection site:

      1. Adults and Adolescents

        • Standard Needle Length: 1 to 1.5 inches (25 to 38 mm).
        • Weight Considerations:
          • Less than 130 lbs (60 kg): 1-inch needle.
          • 130-152 lbs (60-70 kg): 1-inch needle.
          • 152-200 lbs (70-90 kg) for women and 152-260 lbs (70-118 kg) for men: 1 to 1.5-inch needle.
          • Over 200 lbs (90 kg) for women and over 260 lbs (118 kg) for men: 1.5-inch needle.
      2. Children: Aged 1 to 12 years: 5/8 to 1 inch (16 to 25 mm).

      3. Infants: Aged 1-12 months: 1 inch (25 mm). Newborns (0-28 days): 5/8 inch (16 mm).

    For more detailed information and specific guidelines, refer to the CDC and Immunization Action Coalition resources​ (CDC)​​ (CDC)​​ (Immunize.org)​.


Intramuscular injections are a vital method for administering medications, providing rapid and efficient delivery of antibiotics, hormones, and vaccinations. Understanding the proper technique and applications of IM injections is essential for healthcare providers to ensure patient safety and treatment efficacy. For a detailed visual guide, refer to the JoVE video "Intramuscular Injection of Antibiotics, Hormones, and Vaccinations."

By mastering the art of IM injections, healthcare professionals can enhance their practice and provide better care for their patients.

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