From time to time I am asked why someone should consider BHRT over conventional therapy. This basic question usually comes from the idea that “a hormone is a hormone” and there is no difference between the various forms. This view has repeatedly been shot down by various studies showing that different forms of hormones do vary in their effects, good and bad.
The concept of BHRT stems from the idea that if something is missing from the body as in hormone depletion during peri-menopause, menopause or andropause, there can be no better replacement than what was originally there. Our bodies are designed to use those forms and not others, although the body can adapt and use the other forms with varying degrees of side effects and effectiveness. We cannot improve the original hormones. Anything else we put in the body will not do the exact same thing and has the potential to cause side effects the original form did not have.
An example of this is the use of progestins. In the conventional approach to HRT, progestins are used in menopausal women who still have their uterus. These drugs were developed after women using estrogen started getting uterine cancer from unopposed estrogens. Drug companies knew that progesterone would prevent that problem but in those days, there were no readily available sources of progesterone and it couldn’t be patented. This led them to develop “knock-offs” of it which would work orally and protect the uterus without regard to what else they did. Progestins eliminate any cardiovascular benefit from estrogen sources and increase breast cancer risk, while progesterone itself does not. Members of the medical community sometimes use the term progesterone to refer to these progestins as if they were identical even after repeated studies have shown the huge difference between them.
There are similar examples with estrogen and testosterone. In fact, almost all forms of synthetic testosterone have been removed from legitimate use (anabolic steroids) because of these unintended side effects. Maybe we will get to the point that synthetic estrogens and progestins are also discontinued.