What is the maximum injection volume for an intramuscular (IM) injection in adults?

The maximum injection volume for an intramuscular (IM) injection in adults is 3 mL. This volume is recommended to ensure proper absorption and minimize discomfort and tissue damage at the injection site. Administering higher volumes can lead to increased pressure within the muscle tissue, which may cause pain or even muscle damage.

In practice, when giving an IM injection, healthcare professionals also consider the muscle mass of the patient, as larger volumes may be appropriate in certain larger muscle groups like the gluteus maximus. However, 3 mL is a widely accepted and safe upper limit for the vastus lateralis or deltoid muscles.

Other volume options, such as 1 mL, 5 mL, or 10 mL, exceed this guideline under standard practice conditions for IM administration in most adults. While specific situations may warrant exceptions, they are not typical for general practice. Therefore, the 3 mL maximum aligns with established guidelines for safe and effective intramuscular injection.