Editing Subcutaneous administration (section)

====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 subcutaneous injections of insulin.<ref name="insulin2018">{{cite journal | vauthors = Gedawy A, Martinez J, Al-Salami H, Dass CR | title = Oral insulin delivery: existing barriers and current counter-strategies | journal = The Journal of Pharmacy and Pharmacology | volume = 70 | issue = 2 | pages = 197–213 | date = February 2018 | pmid = 29193053 | doi = 10.1111/jphp.12852 | name-list-style = vanc | s2cid = 12848146 | doi-access = free }}</ref> 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.<ref>{{cite web |title=Insulin Human - Drug Usage Statistics |  work = ClinCalc DrugStats Database |url=https://clincalc.com/DrugStats/Drugs/InsulinHuman }}</ref>

Insulin historically was injected from a vial using a syringe and needle, but may also be administered subcutaneously using devices such as [[injector pen]]s or [[insulin pump]]s. 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.<ref name=Taylor />{{rp|722}}