Subcuteanous injection or injection in the fat layer (hypodermis), one of the layers of the skin (cfr picture) is commonly used for injections of insulin by diabetic patients (type I diabetes). However, next to insulin, also vaccines can be administered subcutanously in fatty tissue.
Subcutaneous injection is one of the routes of administration used for vaccination. The three main routes are subcutaneous (SC) injection, intramuscular (IM) injection and intradermal (ID) injection. Each type targets a different skin layer:
- Subcutaneous injections are administered in the fat layer, underneath the skin.
- Intramuscular injections are delivered into the muscle.
- Intradermal injections are delivered into the dermis, or the skin layer underneath the epidermis (which is the upper skin layer). The dermis is, on most places of the human body, only a few mm thick.
Place of subcutaneous injection
Subcutaneous injections can be delivered into the upper arm, above and below the waist – except within a circle of about 5 cm ( 2 inch) around the navel, the upper buttock and the thigh.
Use of subcutaneous injection
Subcutaneous injections are mainly used for patients who have type I diabetes. The patient’s lack of insulin is treated by injecting the substance directly into the fatty tissue, using a so-called “insulin pen” for subcutaneous injection.
Subcutaneous injections are also effective for the administration of other medications and vaccines, such as morphine, diacetylmorphine and goserelin.
Vaccination through subcutaneous injection is, however, not as effective as intradermal vaccination.