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

As Michelle Rust was diabetic and needed insulin, hundreds of family members, friends and volunteers quickly joined searches through woods, hospitals and pharmacies in the area to locate her. —Sophie Sonnenfeld, ABC News, 23 Apr. 2026

May lower blood sugar too much if taken with diabetes medications or insulin. —Megan Nunn, Verywell Health, 23 Apr. 2026

The time of day Dehydration When your blood sugar is high, your pancreas releases insulin to bring it down. —Kaitlin Sullivan, Health, 22 Apr. 2026

Diabetic ketoacidosis is a life-threatening medical emergency that can occur when the body doesn't have enough insulin to allow blood sugar into the cells for use as energy, according to the CDC. —Vanessa Etienne, PEOPLE, 22 Apr. 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