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

After analysis, researchers discovered that when people drank raspberry leaf tea after consuming sucrose, their blood glucose and insulin levels were significantly reduced. —Christina Manian, Health, 5 Dec. 2025

Greater muscle mass is associated with better insulin sensitivity and lower diabetes risk, independent of body fat, according to a study published in The Journal of Clinical Endocrinology & Metabolism. —Dana Santas, CNN Money, 5 Dec. 2025

Some people with diabetes are dependent on insulin, a hormone drug that allows cells to take in blood sugar to use as fuel. —Heidi Moawad, Verywell Health, 3 Dec. 2025

Incorrect low readings can lead to excessive carbohydrate intake or skipped or delayed insulin doses, Abbott said. —Kerry Breen, CBS News, 3 Dec. 2025

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