insulin-like growth factor 1

biochemistry

Also known as: IGF-1, somatomedin

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June 29, 2026

Quick Summary

Insulin-like growth factors (IGFs) are peptide hormones that primarily stimulate growth and can also lower blood glucose levels. They were discovered when studying the effects of biological substances on cells outside the body. IGFs have some insulin-like actions but are less potent in lowering blood glucose. There are two main types: IGF-1 and IGF-2, which bind to different receptors and have distinct tissue actions.

Most of the growth-promoting effects of pituitary growth hormone are mediated by IGFs, especially IGF-1. Growth hormone stimulates tissues like the liver to produce IGF-1, which then promotes cell growth (hypertrophy and hyperplasia) in most tissues, including bone. IGF-1 levels rise during childhood and peak at puberty, decreasing thereafter. IGF-2 production is less dependent on growth hormone and is less significant for linear growth. IGFs likely exert their main actions locally through paracrine and autocrine effects.1

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insulin-like growth factor
There are two IGFs: IGF-1 and IGF-2. These two factors, despite the similarity of their names, are distinguishable in terms of specific actions on tissues because they bind to and activate different receptors. The major action of IGFs is on cell growth. Indeed, most of the actions of pituitary…
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There are two IGFs: IGF-1 and IGF-2. These two factors, despite the similarity of their names, are distinguishable in terms of specific actions on tissues because they bind to and activate different receptors. The major action of IGFs is on cell growth. Indeed, most of the actions of pituitary…
Read More

growth hormone
…release insulin-like growth factors, primarily insulin-like growth factor 1 (IGF-1; formerly called somatomedin). The term insulin-like growth factor is derived from the ability of high concentrations of these factors to mimic the action of insulin, although their primary action is to stimulate growth. Serum IGF-1 concentrations increase progressively with age…
Read More
…release insulin-like growth factors, primarily insulin-like growth factor 1 (IGF-1; formerly called somatomedin). The term insulin-like growth factor is derived from the ability of high concentrations of these factors to mimic the action of insulin, although their primary action is to stimulate growth. Serum IGF-1 concentrations increase progressively with age…
Read More