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

There’s a story about someone who’s been rationing their insulin and the downsides of that. —Senior Television, Los Angeles Times, 9 Jan. 2026

Magnesium supports insulin function and glucose metabolism, while berberine works by improving insulin sensitivity and reducing glucose production in the liver. —Morgan Pearson, Verywell Health, 9 Jan. 2026

Large muscle groups such as the thighs and buttocks play a central role in regulating blood sugar and insulin sensitivity. —Desireé Oostland, Vogue, 8 Jan. 2026

Weight loss drugs mimic the action of this hormone by increasing the secretion of insulin to lower blood sugar. —Jack Guy, CNN Money, 8 Jan. 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