For many people, the term Bio-Identical Hormone replacement is an unknown concept. In the simplest terms, it merely means that when deciding to replace missing hormones during menopause or peri-menopause, we choose the exact forms of the various hormones which the body normally produces, instead of choosing to substitute a form of the hormone which does not occur in the body already.  These substitute hormones are primarily either a drug company’s manipulation of natural hormones to create a patentable molecule or an animal source of the hormone-like Premarin.  In both cases, the result is a new hormone not normally in the human body, with some, but not all of the original hormone’s properties and effects.

Premarin is an estrogen source from the urine of pregnant mares containing many different forms of estrogen, only one of which is a human version.  This form of estrogen is estrone, which has been implicated as the “bad” estrogen, causing an increased risk of breast cancer and blood clots over and above other human estrogens. It is no wonder in retrospect that we had a huge increase in breast cancer incidence beginning 10 years or so after Premarin became the number one prescribed drug in the country.

Another category of hormones we need to consider is progesterone. There is only one human version, but drug companies developed several alternatives, called progestins, early in the history of hormone replacement because real, bio-identical progesterone was not readily available and not effective orally in those days.  It turns out that instead of getting benefit from hormone replacement, these progestins eliminated all the decreased incidence of heart disease we expected to see from just the estrogen, and increased the risk of breast cancer over what estrogen alone would do. The real, bio-identical progesterone preserves this benefit reduces breast cancer risk and has dozens of other effects which the progestins do not have.

For testosterone, which some women need and benefit from, a form called methyltestosterone is still being used, but it can cause liver damage and doesn’t have all the effects of the real, human testosterone.

It is possible to make the case that 40 years ago since we didn’t have other options for hormone replacement, the conventional approach which some physicians still use was acceptable. But now we can do better.

The bottom line on this is that Bio-identical hormones are the only true replacement for what is missing, while the synthetic and animal source hormones are merely substituting an inferior hormone for the correct one. We cannot improve on what the body is already using for these effects.