What is the proper angle for an intramuscular injection?

The proper angle for an intramuscular injection is 90 degrees. This angle allows the needle to penetrate the muscle tissue directly, ensuring that the medication is deposited deep into the muscle where it can be absorbed more effectively. Intramuscular injections require access to larger muscle groups, which are situated at a depth under the skin, and a 90-degree angle is optimal for reaching these muscles without damaging surrounding tissues.

In contrast, angles such as 45 degrees or 30 degrees are generally used for subcutaneous or other types of injections, where the medication needs to be administered into the fatty tissue just beneath the skin rather than into the muscle. A 60-degree angle also does not effectively target the muscle tissue for intramuscular injections, making 90 degrees the standard practice among healthcare professionals for this specific injection type.