Hormones are chemical messengers. Imagine if you will a bike messenger, or a courier of some type, whose job is to deliver instructions from one person to another. If said instructions affected the receiving party in such a way that change is incurred, you could generically refer to the bike messenger as a hormone. There are two basic types of hormones natural and synthetic.
A natural hormone is a substance, usually a peptide or steroid, produced by one tissue and designed to affect the physiological activity of another tissue, or organ. Natural hormones are your body's chemical messengers, and in the same way the bike messenger delivers his information, hormones travel throughout your bloodstream delivering their various chemical messages. Working slowly, over time, they impact many different systems, functions, and physiological processes including:
Natural hormones are generated by the endocrine glands - a special group of cells central to which are the pituitary, pineal, thymus, thyroid, adrenal glands, and pancreas. These hormones are then actually produced within the testes of men, and the ovaries of women.
These natural hormones are quite powerful, requiring only a tiny amount to cause major changes in individual cell, tissue, and organ functioning throughout your entire body. This is why too much or too little of a certain hormone can cause systemic problems. Laboratory tests are used measure the hormone levels in your saliva, blood, urine, and even hair follicles. A blood test is often performed by your physician if you begin to experience the symptoms of a hormone disorder or deficiency. One very common example of hormonal testing is that of the home pregnancy test, which measures pregnancy hormones in urine.
A synthetic hormone is a man-made compound that functions like a natural hormone within the body.
To trace the history of synthetic hormones, back to source we'll have travel back to 1931. A German chemist by the name of Adolf Butenandt was the first to find a way to identify and purify the hormone androstenon, by extracting it hormone from a few liters of urine. This groundbreaking achievement set the stage for the next several years, and what was to become the forefront of the hormone revolution.
Shortly after Butenandt's breakthrough, chemist Leopold Ruzicka (another German) developed a means to synthesize the hormone for human use. The year 1935 saw Ruzicka, along with Butenandt, develop the very first batch of synthetic of testosterone. So profound was their discovery that both Ruzicka and Butenandt were awarded the 1939 Nobel Prize for their work in chemistry.
The use of synthetic testosterone and its anabolic steroid derivatives by athletes as performance-enhancing substances is well-known, and sadly overshadows the incredible medical benefits of male hormone therapies. However, synthetic hormones (of all kinds) are used to improve the lives of hormonally deficient men, women, and children of alike.
Hormone replacement therapy (HRT) and testosterone replacement therapy (TRT) are medically customized hormone regimens (preparation, dosages, and frequency) designed to restore deficient hormonal functioning.
Hormone replacement therapy is a more general term, which refers to the systematic use of any exogenous hormone used to restore normal levels. For example, Synthroid (levothyroxine sodium), a prescription medication used in thyroid hormone replacement therapy, is employed for the treatment of hypothyroidism (an overactive thyroid gland) and the management of hypothyroid symptoms. Synthroid is a synthetic hormone that's identical to your body's naturally secreted thyroid gland hormone thyroxine.
Testosterone replacement therapy is a more specific, treatment regimen used in testosterone deficiencies including andropause, and other causes of low testosterone production. So TRT differs from HRT in that it exclusively uses testosterone preparations to treat its deficiency, whereas HRT can be administered for any type of hormone replacement therapy.