IGF-1

Growth HormonesHormonal BalanceBlood

Insulin-like growth factor 1, or IGF-1, is a hormone similar in structure to insulin that manages the effects of human growth hormone in the body. Like insulin, IGF-1 has glucose-lowering effects. IGF-1 released by the liver is one of the best-characterised effects of growth hormone activity, and the two regulate each other in a feedback loop: growth hormone triggers IGF-1 release, and IGF-1 in turn inhibits the release of growth hormone.

Why it matters: The IGF-1 blood test measures the level of insulin-like growth factor 1 in the blood. IGF-1 is a hormone made in the liver in response to growth hormone, so a high IGF-1 level can mean that the level of growth hormone is also high. A high IGF-1 level is an important marker for diagnosing acromegaly, but IGF-1 can also be elevated because of other conditions such as diabetes, liver or kidney disease, or pregnancy.

Source · Cleveland Clinic — what it is

Source · Mayo Clinic — why it matters, what moves it, related conditions

Reference Range
115.0 – 355.0ng/mL
115
355LowNormalHigh
What Moves It

May increase with:

Growth hormone — IGF-1 is made in the liver in response to it
Associated Conditions
Acromegaly, for which a high level is an important marker in diagnosis
Related Markers
Testosterone (Total)Insulin
Common questions

What is IGF-1?

Insulin-like growth factor 1, or IGF-1, is a hormone similar in structure to insulin that manages the effects of human growth hormone in the body. Like insulin, IGF-1 has glucose-lowering effects. IGF-1 released by the liver is one of the best-characterised effects of growth hormone activity, and the two regulate each other in a feedback loop: growth hormone triggers IGF-1 release, and IGF-1 in turn inhibits the release of growth hormone.

What might a high or low IGF-1 mean?

The IGF-1 blood test measures the level of insulin-like growth factor 1 in the blood. IGF-1 is a hormone made in the liver in response to growth hormone, so a high IGF-1 level can mean that the level of growth hormone is also high. A high IGF-1 level is an important marker for diagnosing acromegaly, but IGF-1 can also be elevated because of other conditions such as diabetes, liver or kidney disease, or pregnancy.

What is the typical reference range for IGF-1?

The general-population reference range shown here is 115 – 355 ng/mL. Reference ranges describe the general population and are not a personal target — discuss your results with your physician.

What can affect IGF-1?

It may be higher with: Growth hormone — IGF-1 is made in the liver in response to it.

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