ACI Medication Administration Practice Test 2025 – The Complete All-in-One Guide to Exam Success

Subcutaneous injections require a gauge that is suitable for delivering medication into the subcutaneous layer of the skin, which is beneath the dermis and epidermis. A gauge of 25-28G is appropriate for this purpose because these thinner needles allow for comfortable injection while minimizing tissue trauma.

Using a smaller gauge (higher number) needle for subcutaneous injections is advantageous as it causes less discomfort for the patient and facilitates a smoother injection process. Thinner needles are also preferable when injecting medications that can be irritating if delivered with a larger gauge needle.

There are circumstances where slightly larger gauges (20-22G or 23-25G) might be used, particularly for larger volumes or specific types of medications, but the most common practice for most subcutaneous injections, like insulin or certain vaccines, aligns with the 25-28G range. This balance of size, comfort, and medication type makes this gauge the most widely accepted for subcutaneous administration.