The Growth Hormone (GH) Serum test measures the level of a vital hormone from the pituitary gland that, in addition to childhood growth, plays a key role in your adult metabolic health. GH is essential for maintaining muscle mass, bone density, and a healthy body composition. This specialized test is used to investigate symptoms of GH deficiency or GH excess (acromegaly). A simple blood draw is required. This test provides a critical, specialized look at a key hormone, helping your doctor get to the root of complex metabolic conditions.