The IGF-1 Blood Test

The blood test that is commonly used for measuring human growth hormone in adults is the IGF-1 test. This lab test does not measure growth hormone itself. Instead it measures the growth factor called insulin-like growth factor #1 (IGF-1).

The reason this test is used is because, once growth hormone is released by the pituitary gland, it only remains in the bloodstream for a few minutes. It is taken in by the liver and is converted into growth factors, with the main one being IGF-1.

Because HGH doesn't remain in the bloodstream for long, unless just by chance your blood is drawn only a few minutes after your pituitary gland has released growth hormone, it won't be accurate. Since IGF-1 remains more stable in the bloodstream for a longer period of time, the test can be done as a random blood draw, at anytime during the day, with no fasting (NPO) required.

Growth Hormone Stimulation Tests

In children and adults who are suspected of having a growth hormone deficiency unrelated to aging, doctors may do what is called a growth hormone stimulation test.

The HGH stimulation test requires the patient to be hooked up to an IV and so should be done in a hospital setting. The doctor then infuses substances such as GHRH, arginine, or glucagon into the body via the IV to try to stimulate the pituitary gland to release growth hormone. Arginine has been commonly used to try to stimulate the pituitary gland but some new research has shown that it may be the least effective/accurate option.

Another option the doctor may use to stimulate the release of growth hormone is called the insulin tolerance test. Some feel this to be the most effective/accurate option, but it carries risks.

For the insulin tolerance test the physician gives the patient insulin via the IV in order to cause hypoglycemia (low blood sugar), which should stimulate a release of growth hormone by the pituitary gland.

For more information about the lab tests that may be used to measure growth hormone and IGF-1, please click below and you will be taken to my detailed article, found at my educational site.

https://www.hgh-pro.com/blood-tests.html

Lisa Wells, RN