What is a Subcutaneous Injection

A subcutaneous injection is administered as a bolus into the subcutis, the layer of skin directly below the dermis and epidermis, collectively referred to as the cutis. Subcutaneous injections are highly effective in administering medications such as insulin, morphine, diacetylmorphine and goserelin.

A subcutaneous injection is absorbed slower than a substance injected intravenously or in a muscle, but faster than a medication administered by mouth

They are also the easiest form of parenteral administration of medication to perform by lay people, and are associated with less adverse effects such as pain or infection than other forms of injection.