An intramuscular injection is a method of delivering medication directly into a muscle. This technique allows for faster absorption of the medication into the bloodstream compared to other methods, such as subcutaneous injections. Common sites for intramuscular injections include the deltoid muscle in the upper arm, the vastus lateralis in the thigh, and the gluteus maximus in the buttocks. Healthcare professionals typically use a syringe and a needle to perform the injection. The needle is inserted at a specific angle to ensure the medication is deposited deep within the muscle tissue. This method is often used for vaccines, hormones, and certain medications that require rapid action.