When women go through menopause their bodies no longer make two important female hormones – estradiol and progesterone. Since the loss of these hormones causes a number of symptoms as well as medical consequences, many women are interested in replacing these hormones. This is what has been called hormone replacement therapy, or HRT. Frequently you hear about bioidentical HRT and you may have questions regarding what it is and if it is something you should consider.
In this blog I will try to answer these questions.
What does the term bioidentical really mean?
Hormones labeled as being bioidentical imply that they are identical to those that the body makes. For instance, insulin preparations and thyroid supplements are available in bioidentical forms. Taking bioidentical drugs represents the ideal option since they presumably will behave exactly as those produced by the body and not be perceived by the body as being foreign.
Unfortunately, it is not always possible to create these ideal versions, and frequently pharmaceutical companies come up with drugs that are very similar to the natural hormones in the way they function, but are not identical in their molecular structure. Thus they can have some effects that differ from their natural counterparts.
This was the case when HRT became popular back in the 1950’s and 60’s. Creating a product identical to the estrogen made in the ovaries was not commercially feasible, so a major drug company came up with the idea of extracting estrogens from horses’ urine. This led to the development of the drug Premarin (the name coming from pregnant mare’s urine). Premarin became one of the most widely prescribed drugs at the time.
The other hormone produced by the ovaries that is used in menopausal hormone treatment is progesterone. It is very difficult to make progesterone so, early on, drug companies came up with ways to make synthetic drugs similar to progesterone. These are called progestins. Progestins were initially developed for use for contraception and they continue to be a component in the birth control pills prescribed today.
What led to the development of bioidentical hormones?
Premarin and a synthetic progestin were used for several decades to treat hot flashes and other menopausal symptoms and they were very effective. However, in 2003, a major study assessing the risks and benefits of hormone treatment was published. This was the Women’s Health Initiative study (WHI). The drugs used in the study were Premarin and a synthetic progestin called medroxyprogesterone. As it turns out, this study found that women who took these particular hormones developed more adverse effects than women not taking any hormones. And even though the risks were very small and there were shortcomings of the study, popularity for menopausal hormone treatment plummeted. Women were afraid to take Premarin and medroxyprogesterone and doctors were reluctant to prescribe them. (To learn more about this important study, please review my blog describing the WHI.)
However women continued to have hot flashes, mood swings, thinning of the bones, vaginal dryness, and other menopausal symptoms. Thus there was a great interest in finding an alternative treatment. This is where the concept of using bioidentical hormones blossomed. A number of compounding pharmacies began offering various products that contained estrogen compounds, progesterone, and even testosterone. Unlike the hormones used in the WHI study, these were marketed as being identical to those produced by body. This concept appealed to women and a number of healthcare providers began writing prescriptions for bioidentical hormones. These were taken to compounding pharmacies where they were prepared and dispensed.
What is compounding and what is a compounding pharmacy?
A compounding pharmacy is a specialized pharmacy whose pharmacists are trained to create unique formulations of medications that can be used in special situations. Although drugs produced by commercial pharmacies are generally used as the raw materials, they are re-formulated into products with customized concentrations or delivery systems.
Because compounded products for HRT are described as being identical to what the ovary makes, and not synthetic, there is the impression that these are safer than those drugs used in the WHI study. And because they are very effective in treating menopausal symptoms they have become very popular. Within a few years following the WHI, the number of prescriptions written for compounded hormones surpassed the number of prescriptions written for Premarin and medroxyprogesterone. And even today, millions of women shy away from commercially prepared hormones – choosing instead compounded products marketed to be “bioidentical.”
Are there commercially produced bioidentical hormones?
As noted, for many years the choices for HRT were very limited and consisted primarily of Premarin and synthetic progestins. However times have changed. Today, there are many commercially produced estradiol products and any HRT preparation that lists its generic ingredient as estradiol or 17-beta-estradiol would be considered to be bioidentical. It is available in many forms, such as pills, creams, sprays, vaginal preparations, and patches. When applied to the skin in the form of a patch or cream, estradiol behaves nearly identical to a woman’s natural estradiol. If it is taken orally, it is metabolized slightly differently and this leads to some mild changes in how it behaves in the body. (To learn more about this, see my blog describing the differences in hormone preparations.) Although other bioidentical female hormones such as estrone and estriol are available, estradiol is the principle type of hormone that benefits women the most.
Progesterone is the other hormone made by the body and it too is available in a variety of forms. Although compounding pharmacies offer progesterone in the form of creams and vaginal preparations, it is only available commercially for HRT use in the US in the form of a pill. Progesterone applied to the skin is not absorbed reliably and most experts in menopause caution that these topical progesterone products should be avoided. Progesterone vaginal preparations are available in some countries outside of the US.
Finally, it is worth noting that all of the commercially available estradiol and progesterone products are derived from plants such as yams and soy. Chemists tweak the natural hormones contained in these plants, converting them to the molecular structure of the hormones made by the ovaries.
Does the type of pharmacy matter?
The next consideration is where to purchase the hormones. They all require a prescription from a licensed health care provider. Since the WHI was published many women continue to obtain their hormones through compounding pharmacies as opposed to the traditional retail pharmacies.
Many menopause societies, such as the North American Menopause Society encourage women to only use the commercial FDA-approved products sold through the major commercial pharmacies. This is because compounding pharmacies do not have the same government oversight as the large pharmaceutical companies. While there are many reputable compounding pharmacies, there have been reports where it was determined that the products dispensed did not contain the exact quality and quantity of hormone compounds indicated on their labeling. In addition, and even more troubling, is that in some cases impurities and other contaminants were detected in some of these products.
The bottom line
Hopefully this article clears up any confusion you may have regarding what is meant by bioidentical hormone therapy. To summarize:
- It makes sense to use body-identical preparations for hormone replacement therapy.
- Estradiol and natural progesterone are considered body-identical.
- In the case of estradiol, applying it to the skin allows it to act in a nearly body-identical way.
- FDA-approved products are available and are generally regarded as the best options when it comes to quality control and oversight.
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