Which needle length is appropriate for a subcutaneous injection given at a 45-degree angle?

For a subcutaneous injection administered at a 45-degree angle, the appropriate needle length is 5/8 inch. This length is ideal for delivering medication into the subcutaneous tissue, which lies beneath the skin but above the muscle tissue.

Choosing a 5/8 inch needle specifically allows for optimal penetration without risk of reaching the muscle layer, which is essential for subcutaneous injections designed to deliver medications like insulin or heparin. A needle that is too short may not adequately reach the subcutaneous layer, while one that is too long could inadvertently intrude into the muscle.

Understanding the proper technique and appropriate needle selection is crucial for effective and safe medication administration, minimizing discomfort, and ensuring the medication's intended absorption.