How are human hormones defined in the body and how are they measured? I understand that blood tests can be used to measure the amount of a hormone in the body, but how do we know which hormone controls what body function. For instance, how can we prove that testosterone controls growth hormones and muscle building.

  • 1
    Hi Cody, welcome to MedSci. Your question is rather too broad. What research have you done on your own? An answer to this would almost be an introductory endocrinology textbook, so you're going to need to narrow it down. You've asked three questions here. I would suggest asking just one. You can ask the other two later.
    – Carey Gregory
    Jan 10 '19 at 1:57