You don't need a degree in endocrinology to know that hormones are responsible for exerting powerful effects on the human body. Conversely, women have learned that most of the bad and some of the good that men do can be explained by their levels of testosterone. Estrogen and testosterone are steroid hormones, and levels of these chemicals in the body define sexuality and regulate behavior. The human body also manufactures protein hormones.
Adrenaline is a protein hormone, and so is insulin.
Human growth hormone is also a protein. This hormone was much more powerful than human growth hormone. The resemblance ends when the potency of IGF-I is compared to insulin. Hundreds of studies have identified IGF-I as a KEY factor in the growth of prostate cancer. Eat pizza with mozzarella or Parmesan on pasta, ice cream or yogurt, and you deliver this hormone to your body.