insulin

noun

in·​su·​lin ˈin(t)-s(ə-)lən 

: a protein pancreatic hormone secreted by the beta cells of the islets of Langerhans that is essential especially for the metabolism of carbohydrates and the regulation of glucose levels in the blood and that when insufficiently produced results in diabetes mellitus

Examples of insulin in a Sentence

Recent Examples on the Web

Zverev, who has Type 1 diabetes and checks his glucose levels throughout his matches, gave himself an insulin injection on two occasions—in the midst of holding down 12 consecutive points on his serve. — Corey Seymour, Vogue, 13 Sep. 2026

McEvoy, who leads Insulet, the maker of the wearable, tubeless Omnipod insulin pump, said designing better technology requires understanding the details of patients’ days—not simply examining their clinical data. — Angela Haupt, Time, 11 Sep. 2026

Pastor said the claim that the boy refused insulin is a false narrative aimed at blaming the child. — Jacques Billeaud, Los Angeles Times, 4 Sep. 2026

Magnesium supports insulin signaling by helping to activate enzymes inside your cells that regulate how your body uses glucose and responds to insulin. — Teresa Maalouf, Verywell Health, 4 Sep. 2026

Word History

Etymology

New Latin insula islet (of Langerhans), from Latin, island

First Known Use

1914, in the meaning defined above

Phrases Containing insulin

• insulin-dependent diabetes
• insulin-dependent diabetes mellitus
• insulin-like growth factor
• insulin resistance
• insulin resistance syndrome
• insulin shock
• non-insulin-dependent diabetes
• non-insulin-dependent diabetes mellitus

Kids Definition

insulin

noun

in·​su·​lin ˈin(t)-s(ə-)lən 

: a hormone that is produced by the pancreas and is necessary for the normal use of glucose by the body

Medical Definition

insulin

noun

in·​su·​lin ˈin(t)-s(ə-)lən 

: a protein hormone that is synthesized in the pancreas from proinsulin and secreted by the beta cells of the islets of Langerhans, that is essential for the metabolism of carbohydrates, lipids, and proteins, that regulates blood sugar levels by facilitating the uptake of glucose into tissues, by promoting its conversion into glycogen, fatty acids, and triglycerides, and by reducing the release of glucose from the liver, and that when produced in insufficient quantities results in diabetes mellitus see iletin