What is the appropriate injection length for a subcutaneous injection?

For a subcutaneous injection, the appropriate injection length typically ranges from 1/2 inch to 5/8 inch. This length is ideal because it allows for the needle to penetrate the skin and reach the subcutaneous tissue without going too deep, which would risk injecting into muscle. The layers of tissue are crucial to consider, as subcutaneous injections are administered into the fat layer between the skin and muscle.

Using a needle that is too short may not effectively deliver the medication into the intended tissue, while a needle that is too long could penetrate deeper and cause injury to underlying structures. The typical sites for subcutaneous injections include the abdomen, thighs, and the back of the arms, where there is adequate fatty tissue for safe administration.

Considering the alternative choices, the other lengths either exceed the requirements for an effective subcutaneous injection or are not standard practice. Therefore, the range of 1/2 inch to 5/8 inch is specifically recommended for ensuring the medication is delivered effectively into the correct tissue layer.