Injection routes and sites

Subcutaneous: 45 to 90 degrees depending on tissue, abdomen, outer thigh, back of the arm. Rotate sites. Do not aspirate for heparin or insulin, and never massage after heparin. Intramuscular: 90 degrees. Ventrogluteal is the safest site in the adult; vastus lateralis in the infant. Deltoid only for small volumes, up to about 1 mL. Intradermal: 5 to 15 degrees, bevel up, a visible wheal. Intravenous: verify patency and check for infiltration and phlebitis at every use. Maximum intramuscular volume: 3 mL in a well-developed adult muscle, less in a thin or older person.

Clinical content reviewed by Ducamelle Louis, Registered Nurse