Bioidentical Hormones: Facts and hype
Menopause is described as a woman’s ‘third age’. Most women will experience at least some of the menopausal symptoms that come with that phase of life. The intensity and duration of the symptoms vary from person to person. Moreover, some symptoms are transient for most women, experienced at the onset of menopause and gradually subsiding and eventually resolving completely. This tends to be the case with hot flashes and night sweats. Other symptoms start gradually a few months after menopause onset and tend to be progressive. Vaginal dryness and reduced libido are two such examples.
The physiological basis of menopause
Menopause onset is a result of the cessation of estrogen hormone production by the ovaries. Menstrual periods will cease and that is the most notable manifestation of this. However, estrogen hormone has a number of functions in the body apart from facilitating the menstrual cycle. This is why the deficiency of this hormone is manifested not only in the cessation of periods but these other symptoms which include:
- Hot flushes (flashes)
- Night sweats
- Mood swings
- Reduced or loss of libido
- Vaginal dryness
- Loss of bone mass which could lead to osteoporosis
Hormone Replacement Therapy (HRT)
To ameliorate the effects of loss of estrogen and control the symptoms, hormone replacement therapy (HRT) has traditionally been used. This is still the most effective remedy today. However, we know a lot more about the unwanted effects of HRT today than we did even a decade ago. As such, advice on taking HRT has changed a lot over the last few years. This is from the timing of starting the HRT, the duration for which it should be used, the route (oral, through the skin, implant etc.) and the type. This hub is meant to address the subject of the type of HRT and specifically Bioidentical Estrogen Hormone Therapy.
What is Bioidentical Hormone Therapy?
This is important and I cannot stress this enough: Bioidentical is not the same as ‘natural’. Now that we have nailed that, and I will come back to it shortly; let’s see what bioidentical is. "Bioidentical" refers to the chemical structure of hormones and not the source. It means bioidentical hormones and hormones produced in the body (also called endogenous), have exactly the same chemical and molecular structures. Natural hormones refer to the source meaning these hormones are derived from plants or animals. Plant or animal-sourced hormones are natural but they are not bioidentical. In other words, they do chemically differ from those produced in the human body.
Bioidentical hormones are also plant derived, usually from soy or yams. However, they undergo chemical processing to make them identical to those produced by the body. In their natural form they are not bioidentical.
Natural but not Bioidentical
Safety of Bioidentical Hormone Therapy products
In the United States, there are two distinct groups of Bioidentical Hormone Therapy products. These are:
Standardized FDA-approved Bioidentical Hormone Products
Custom-compounded Bioidentical Hormone Products
As the names suggest, the standardised approved products are those products which have undergone and passed the rigorous safety and quality tests. They are standard and therefore will be the same wherever they are obtained. Also the contents in terms of ingredients and dosage are as stated on the package.
Custom-compounded hormones are individualised and therefore not FDA-approved since that will be impractical. The idea behind these preparations is that they should be tailor-made for each person according to their need. As such, each preparation will have different hormone combinations and even delivery methods could be different. These hormone preparations are regulated by State boards of pharmacy and there are specific guidelines for appropriate use. However, they remain outside federal laws. One aspect of these custom-compounded hormone preparations that makes assessment of safety and side effects difficult is their heterogeneity. Because each preparation for each individual is inherently different from the next person, you cannot generalise. This has created a potentially dangerous impression that these are definitely safe. This is not helped by the fact that most individuals who seek these out do so because they are convinced that they are safe and risk-free. That mind-set creates a subliminal disincentive. Individualisation creates an allure of being ‘perfect for me’ but this is not the same as ‘safe’.
Absolute safety of Bioidenticals is a myth
One of the most important roles that any consulting and prescribing physician plays is to inform their patient to allow them to make well-informed decisions. In that regard, the issue of safety of prescribed medicines is paramount. For a physician like me, if you declare a product to be ‘safe’ or ‘safer’ than another product, that claim has got to be based on solid scientific evidence and not supposition. Since the compounded hormone preparations have not undergone the requisite research to prove that they are safer than the standard preparations, no such claim should be made even if it is strongly supposed. It may true but the evidence is not there; at least not yet.
Some conventional HRT preparations are ‘natural’
Another misunderstanding among users that need to be clarified is the fact that some of the conventional HRT preparations are actually natural. Premarin, as shown in the picture above, is a prime example. This hormone, widely prescribed for many years both in Europe and North America is a conjugated equine estrogen derived from pregnant mare urine. However, it is not bioidentical. In other words, even though it is an estrogen, it is not chemically similar to estrogen produced by humans.
On the other hand Estrace is a bioidentical estrogen, exactly similar to the estrogen produced in the human ovaries. Similarly estrogen contained in Climara or Vivelle-Dot patches are bioidentical. When I (or any other gynaecologist) am prescribing these, I will not be justified in describing them as ‘safer’ than the non-bioidentical preparations. I can only say they are thought to be safer and that is the full extent of the truth.
The allure of individualised hormone level testing
One attraction of custom-compounded Bioidentical Hormones is the availability of tests, both salivary and blood of the various hormone components to ‘ensure the combination is just right’. Although the logic might be quite appealing for the user, in fact the concept has dubious scientific basis as it appears to ignore the fact that each woman is unique and has varying proportions of different hormones. There is also the fact that test results of hormone levels can and do often correlate poorly with the clinical need. In other words, there are a lot of hormone replacement users whose blood results show ‘normal’ results but who still experience significant, even debilitating menopausal symptoms. Testing is therefore of limited value.
Salivary hormone testing: This mode of testing is attractive to many people because of the ease of collecting the sample. However, results may not actually be as reliable as the ones you get in a blood test. Apart from the results being non-standardised, there are many factors that influence them. It is an area of uncertainty that users should not brush over.
Types of Estrogen and their safety profile
It is important to be aware that the body produces estrogen in many forms. The most potent type of estrogen produced by the ovaries is called estradiol. A much weaker estrogen type is called estriol or E3. Most custom-compounded Bioidentical Hormone preparations utilise this weaker estrogen estriol. The reason behind this is because it is claimed to stimulate breast tissue much more weakly thereby making it safer. However, there are studies which conclusively show that the increased dosage and frequency of application required to achieve clinical benefit actually result in the stimulation of the breast and uterine tissues to a similar extent to estradiol, and therefore any perceived protective effect may be lost. There is also the fact that estriol has been shown to lack the bone protective effect of its more potent cousin (estradiol) and therefore users whose intention is to prevent osteoporosis would not be achieving their goal by using these preparations.
Separate facts from hype
This hub addressed the issue of bioidentical estrogen hormone preparations. I will address the issue of other hormones in a separate hub. Suffice it to say here that the idea of tailor-made hormone preparations is very attractive and, in the fullness of time, may prove to be a move in the right direction. However, we are not yet in the Promised Land.Like for all drug preparations, it is important to distinguish what is desirable from what is proven and proceed with caution accordingly. To re-cap:
- Bioidentical is not the same as Natural.
- There are some natural hormones that are not bioidentical
- Standardised Bioidentical Hormone products are FDA-approved as they have gone through the rigorous safety and quality testing while Custom-compounded Bioidentical Hormone products, made specifically for each individual, are not.
- The concept of an absolutely safe hormone preparation is a myth
- There is, so far, no evidence that individualised hormone testing and monitoring that forms the bed-rock of Custom-compounded Bioidentical Hormone Products is beneficial.
- Estriol (E3), which is the main type of estrogen used in the Custom-compounded Bioidentical Hormone products is effective for menopausal symptoms but lacks the bone protective effect seen with Estradiol. Standardised Bioidenticals such as Vivelle-Dot contain the more potent Estradiol.