Maximum Volume for Deltoid Intramuscular Injection

Volume Guidelines by Age

The American Academy of Pediatrics recommends a maximum volume of 0.5 mL for children aged 3 years and older and adults, with some vaccines using 0.25 mL for younger children (6-35 months) 1, 2
For infants and young children (6-35 months), the recommended volume is 0.25 mL or 0.5 mL, depending on the specific vaccine product, with 0.25 mL being the recommended dose from multidose vials for Afluria 1
A 0.5 mL prefilled syringe should never be split into two 0.25 mL doses due to sterility concerns 2

The Centers for Disease Control and Prevention recommends the deltoid muscle as the preferred injection site for older children and adults, while the anterolateral thigh is recommended for infants and young children 1, 3, 4
For adults and older children, a needle length greater than 1 inch may be needed to penetrate muscle tissue, while children with adequate deltoid mass may require a needle length of 7/8 to 1.25 inches 3, 4

Larger volumes risk inadequate muscle penetration and subcutaneous deposition, and excessive volume can cause local pain, reduced absorption, and increased adverse reactions 2, 3, 4
For volumes exceeding 0.5 mL, the Centers for Disease Control and Prevention recommends considering alternative sites, such as the anterolateral thigh (vastus lateralis), which accommodates larger volumes and provides more rapid absorption for certain medications 5

The American Academy of Pediatrics recommends injecting in the middle third of the deltoid muscle to avoid major neurovascular structures 6

The middle third of the deltoid is safest; avoid the upper or lower portions where neurovascular structures are at higher risk, as recommended by the American Academy of Pediatrics 6