Question: What is the current practice for giving an IM injection across the lifespan? Should the nurse aspirate the syringe?...

Complete Question: What is the current practice for giving an IM injection across the lifespan? Should the nurse aspirate the syringe? CDC recommends no per my resources. Please provide guidance.

Several members of the Clinical Practice Committee reviewed and investigated an answer to this question.

Answer: Aspiration is the process of pulling back on the syringe plunger by applying negative pressure for 5-10 seconds after the needle has been inserted into tissue, but before administration of the medication (CDC, 2017; Sepah et al, 2017).

The rationale for aspiration has traditionally been to avoid inadvertent intravenous administration of the medication. This concern is based on tradition, but not supported by evidence (CDC, 2017; Sepah et al, 2017). In addition, many auto-disable safety syringes prevent aspiration, making the process impossible during medication administration (Sepah et al, 2017).

The CDC recommends against aspirating during IM injection of vaccines (2017). This recommendation is based on research which indicated that aspiration resulted in increased pain during IM injection in infants, without any apparent benefit (Ipp, Taddio, Sam, Goldbach & Parkin, 2007).  The CDC (2017) also notes that the length of the needle should be carefully selected in order to ensure the medication reaches the muscle tissue, but not so long that it reaches underlying tissue, including blood vessels. Recommended sites for intramuscular injection generally do not include blood vessels, which should eliminate the need for aspiration.

The CDC guidelines are directed specifically at administration of vaccines and toxoids, which have a low risk of adverse effects if they are injected systemically.

The CDC recommends this technique when administering IM vaccinations to adults:

  • Follow standard medication administration guidelines for site assessment/selection and site preparation. The nurse should consider the size of the muscle, viscosity of the medication, and volume to be administered when selecting the needle length and gauge. A 22-25 gauge needle is generally appropriate.
  • To avoid injection into subcutaneous tissue, spread the skin of the selected vaccine administration site taut between the thumb and forefinger, isolating the muscle. Another technique, acceptable mostly for pediatric and geriatric patients, is to grasp the tissue and "bunch up" the muscle.
  • Insert the needle fully into the muscle at a 90° angle and inject the vaccine into the tissue.
  • Withdraw the needle and apply light pressure to the injection site for several seconds with a dry cotton ball or gauze.

The following recommendations are based on currently available evidence. In order to avoid unnecessary aspiration during IM medication administration, and minimize the risk of inappropriate systemic (intravenous or intra-arterial) administration:

  • Select the site and needle size which are most appropriate for the patient. This will increase the likelihood of medication administration into muscle tissue, and not blood vessels (CDC, 2017).
  • Aspiration is generally not recommended during IM injection of medications with a low risk of adverse effects if the medication is inadvertently injected systemically instead of via the IM route.
  • Aspiration may be indicated if the medication has a high risk of adverse effects and if it is inadvertently administered systemically instead via the intended IM route (Sepah et al., 2017).


  • Centers for Disease Control and Prevention. (2017). Vaccine administration: General best practice guidelines for immunization: best practices guidance of the advisory committee on immunization practices (ACIP). Retrieved from
  • Ipp, M., Taddio, A., Sam, J., Goldbach, M. & Parkin, P.C. (2007). Vaccine-related pain: Randomised controlled trial of two injection techniques. Archives of Disease in Childhood, 92(12), 1105-1108.
  • Sepah, Y., Samad, L., Alrag, A., Halim, M.S., Rahagopalan, N. & Khan, A.J. (2017). Aspiration in injections: Should we continue or abandon the practice? F1000 Research, 3(157).
  • Sisson, H. (2015). Aspirating during the intramuscular injection procedure: A systematic literature review. Journal of Clinical Nursing, 24(17), 2368-2375.
  • Thomas, C.M., Mraz, M. & Rajcan, L. (2016). Blood aspiration during IM injection. Clinical Nursing Research, 25(5), 549-559.
  • Shepherd, E. (2018). Injection technique 1: Administering drugs via the intramuscular route. Nursing Times, 114(8), 7.

(Updated Jan. 2019)
(Updated Jul. 2016)
(Published 2014)