Hormones are signaling molecules or chemical messengers, produced by glands and secreted directly into our blood, transported to various parts of the body where they regulate complex activities of our body. Some of the bodily activities controlled by hormones are digestion, respiration, sleep, excretion, reproduction, etc.
The hormones are secreted by endocrine (e.g., pituitary, thyroid, pancreas, etc.) glands and after they carry out their purpose, they are destroyed. The breakdown of the hormone may be carried out by the liver or tissues of the target organ. In the liver, hormonal breakdown takes place in two phases. At the end of these phases, hormones are converted to water-soluble compounds, passed onto the kidneys and are removed through the urine. Some athletes may consume hormones (or hormone inducing drugs) to enhance their performance and this illegal intake can be detected by urine testing.