The health media praises bio-identical hormones as today’s answer to all of women’s midlife problems. However, when we ask our family doctors for further information or for a prescription, we are often met with a less than positive response. Does this mean that bio-identical hormones are bad? I will try to explain.
The Definition of Bio-identical
The term “bio-identical hormones” was coined to describe a hormone that is the exact same molecular structure as the hormone naturally produced by your body. It is “Mother Nature’s” design as opposed to the synthetic hormones created by pharmaceutical companies. A bio-identical hormone may be synthesized in a lab, but care is taken to create a molecule that is identical in structure to the natural form of the hormone. Substrates such as soy or wild yam are used because they happen to contain substances that are easily changed into the desired bio-identical structures.
Bio-identical vs. Synthetic
It has become important to distinguish between bio-identical and synthetic hormones because they do not behave the same way in the body. Most hormones that are prescribed are synthesized in a lab, so technically they are “synthetic”. Hormones that are synthesized to be identical to the hormones made naturally by the body are called bio-identical. The hormones that are synthesized to be a bit different from natural hormones have been called “synthetic”, although it may be more accurate to call them “non-bio-identical”. Why would a lab make a hormone that is not exactly the same as what the body makes? The answer is related to the fact that patents are not given for natural substances. In order for a pharmaceutical company to have ownership of a particular medication for the purposes of marketing and profit, the company must have a patent. In order to acquire a patent, pharmaceutical companies must make some change to the natural molecule to make it “unnatural”. Unfortunately, because the patented hormones are structurally different from natural hormones, they behave somewhat differently.
Why Synthetic Hormones Act Differently than Bio-identical Hormones
The body has a finely-tuned system of communication that is often described as “lock and key”. In order for a hormone to communicate with a cell in the tissue, it must fit into a receptor that sits in the cell wall. Each hormone has its own receptor, specifically made for it, so when the hormone binds onto the receptor, it fits as a key fits into a lock. The structure of the hormone must fit exactly into the structure of its receptor in order for the hormone to exert its full effect on the tissue. Pharmaceutical companies have been able to create synthetic hormones that fit pretty well, but not exactly. These synthetic hormones may exert some of the desired effect, but they will never function like a natural hormone in the body – sometimes with very unfortunate results. A good example of this was seen in the Women’s Health Initiative (WHI) trial in 2002. The WHI studied Premarin (estrogens derived from the urine of pregnant mares) and Provera (synthetic progesterone) and was stopped early because of adverse outcomes. One group was given Premarin alone and another group was given Premarin and Provera. The group taking both Premarin and Provera had the worst results. This makes sense when we know that natural progesterone protects us from many of the negative effects of estrogen that synthetic progesterone does not.
How to Ensure You Are Using Bio-identical Hormones
The most reliable way to ensure that you are using bio-identical hormones is to seek care from a physician who is knowledgeable and experienced in prescribing them, but that may not always be possible. Conventional medical training does not distinguish between synthetic and bio-identical hormones, and therefore, a family doctor may not be familiar with the importance of using bio-identical forms when prescribing hormones.
Usually bio-identical hormones are prescribed as a cream so the hormone is absorbed through the skin, but there are other forms available that the family doctor should be familiar with. Pharmaceutical companies, although unable to patent the bio-identical hormone, have been able to patent their “unique delivery systems”. These delivery systems include topical bio-identical estrogen in a gel (Estrogel) or a patch (Estradot or Estraderm). Bio-identical progesterone is available in a capsule in which it is micronized in peanut oil (brand name: Prometrium) and taken orally. These forms of hormone prescription have been available in the medical community for many years and therefore, even though “bio-identical hormone” is not a term used in the medical schools or the medical community, family doctors may actually prescribe them without realizing that they are doing so.
I am optimistic that as patients become more informed and continue to ask for bio-identical hormones, the medical community will respond by recognizing and acknowledging the benefits of a natural hormone over a synthetic one.