IGF-1 (insulin-like growth factor 1) is a hormone that manages the effects of growth hormone (GH) in your body. Together, IGF-1 and GH promote normal growth of bones and tissues. The growth hormone (GH) marker Insulin-like growth factor-1, which is measured by this test, is present in the blood. The growth hormone encourages the development of tissues and bones. Adults who have higher GH levels may also experience deep husky voices, larger-than-normal facial features, excessive perspiration, bone thickening, irregular menstrual cycles in women, and erectile dysfunction in men. Giving GH supplements helps address low GH levels. Higher GH levels are a symptom of pituitary tumours as well as gigantism and acromegaly in children and adults, respectively.