IGFBP-3 Unit Converter

IGFBP-3 (insulin-like growth factor binding protein 3) is the most abundant IGF binding protein in the bloodstream. It serves as the primary carrier for IGF-1 and IGF-2, the hormones that mediate most of growth hormone's effects in the body.

IGFBP-3 forms a large ternary complex with IGF-1 and another protein called acid-labile subunit (ALS). This complex carries approximately 75-90% of circulating IGF-1, extending its half-life from minutes to many hours and regulating how much IGF-1 reaches tissues.

Because IGFBP-3 production is regulated by growth hormone, its blood level reflects overall GH status. Unlike GH itself, which fluctuates widely throughout the day, IGFBP-3 remains relatively stable, making it a useful marker for assessing the GH-IGF axis.

IGFBP-3 is produced primarily in the liver, with additional production in the kidneys, stomach, and other tissues. Its synthesis is stimulated by growth hormone, mainly through GH's effects on IGF-1 and acid-labile subunit.