An insulin pump with a subcutaneous infusion site A<unk>  is administered into the fatty tissue of the subcutaneous tissue, located below the dermis and epidermis. They are commonly used to administer medications, especially those which cannot be administered by mouth as they would not be absorbed from the gastrointestinal tract. A<unk>  is absorbed slower than a substance injected intravenously or into a muscle, but faster than a medication administered by mouth. Medications Medications commonly administered via<unk>  or infusion include insulin, monoclonal antibodies, and heparin. These medications cannot be administered orally as the molecules are too large to be absorbed in the intestines.<unk> s can also be used when the increased bioavailability and more rapid effects over oral administration are preferred. 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. Insulin Perhaps the most common medication administered subcutaneously is insulin. While attempts have been made since the 1920s to administer insulin orally, the large size of the molecule has made it difficult to create a formulation with absorption and predictability that comes close to<unk> s of insulin. People with type 1 diabetes almost all require insulin as part of their treatment regimens, and a smaller proportion of people with type 2 diabetes do as well - with tens of millions of prescriptions per year in the United States alone. Insulin historically was injected from a vial using a syringe and needle, but may also be administered subcutaneously using devices such as injector pens or insulin pumps. An insulin pump consists of a catheter which is inserted into the subcutaneous tissue, and then secured in place to allow insulin to be administered multiple times through the same injection site. Recreational drug use<unk>  may also be used by people to (self-) administer recreational drugs. This can be referred to as skin popping. In some cases, the administration of illicit drugs in this way is associated with unsafe practices leading to infections and other adverse effects. In rare cases, this results in serious side effects such as AA amyloidosis. Recreational drugs reported to be administered subcutaneously have included cocaine, mephedrone, and amphetamine derivatives such as PMMA.
Subcutaneous injection
Subcutaneous infusion
Intramuscular injection
Intradermal injection
Transdermal spray
Intraperitoneal injection
Oral administration
Subcutaneous implant