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

Other diets included the Planetary Health Diet Index, which is an environmentally aware eating regimen, and specialized diets for lowering insulin and inflammation levels. —Tom Gavin, EverydayHealth.com, 23 Feb. 2026

To move these from your blood and into your cells, your pancreas releases insulin (a hormone that helps regulate blood sugar). —Lauren Panoff, Verywell Health, 22 Feb. 2026

Fiber slows the absorption of sugar into the bloodstream, while LAB can improve insulin sensitivity and reduce glucose absorption. —Jillian Kubala, Health, 20 Feb. 2026

Taking a medication like metformin, which improves insulin sensitivity regardless of weight loss, can help some women with PCOS ovulate regularly. —Deanna Pai, SELF, 20 Feb. 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