insulin

noun

in·​su·​lin ˈin(t)-s(ə-)lən How to pronounce insulin (audio)
: 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
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
That is why companies are moving to special pens to make injecting prescription GLP-1s and insulin less complex for untrained people. — C. Michael White, The Conversation, 7 Aug. 2026 But every vial of insulin or GLP-1 medication on a pharmacist’s shelf is the product of decades of clinical trials and safety testing. — Los Angeles Times, 6 Aug. 2026 For decades, they’ve been used to deliver vaccines, insulin, hormone treatments, and other medications through the skin. — Maryna Holovnova, New Atlas, 6 Aug. 2026 And in mice fed a fatty, sugary diet, shutting the pathway down in the liver curbed weight gain, cleared out fat and improved insulin sensitivity. — Jacek Krywko, Scientific American, 5 Aug. 2026 See All Example Sentences for insulin

Word History

Etymology

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

First Known Use

1914, in the meaning defined above

Time Traveler
The first known use of insulin was in 1914

Phrases Containing insulin

Browse Nearby Words

insulator
insulin
insulin-dependent diabetes
See all Nearby Words

Cite this Entry

“Insulin.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/insulin. Accessed 11 Aug. 2026.

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Kids Definition

insulin

noun
in·​su·​lin ˈin(t)-s(ə-)lən How to pronounce insulin (audio)
: 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 How to pronounce insulin (audio)
: 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

More from Merriam-Webster on insulin

Nglish: Translation of insulin for Spanish Speakers

Britannica.com: Encyclopedia article about insulin

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