Natural or bioidentical hormones are plant-derived products closely resembling the oestrogen, progesterone and testosterone produced in the body. The hormones are made up (compounded) in pharmacies to provide individualised doses to relieve the symptoms of menopause.

Bioidentical hormone therapy is marketed as natural, safe, risk-free, age-reversing, sex-enhancing and even cancer-preventing. But not only is the term bioidentical in this context a misnomer, the products pose a serious safety risk.

The multi-billion-dollar bioidentical hormone industry is rising in popularity. This has been fuelled in part by the findings of the 2002 American Women’s Health Initiative study. The study authors reported that conventional hormone replacement therapy (HRT) contributed to increased risks of heart disease, breast cancer, venous thromboembolism and stroke.

A number of subsequent reviews showed the conclusions of the study were incorrectly reported. But these highly publicised findings continue to have a detrimental impact on women’s perceptions of the safety of HRT.

The review and subsequent studies found that giving HRT to symptomatic women in their early 50s (and not in their 60s or 70s) improves menopausal symptoms, and hence quality of life. It may reduce the risk of premature death, heart disease, fractures, colorectal and endometrial cancers (with combined continuous therapy) and diabetes.

It was also found that any increased risk for breast cancer is generally negligible for those undergoing less than five years of therapy.

While the risks and benefits of HRT are known, the same cannot be said for bioidentical hormones, which have not been subjected to rigorous testing. These are not approved by Australia’s regulator, the Therapeutic Goods Administration, or the United States Food and Drugs Administration.

The bioidentical hormone industry has made a number of unsubstantiated claims that ought to be corrected.

Claim 1: bioidentical hormones are more natural

The term natural implies the product isn’t synthetic or artificial, which is misleading. All plant-derived hormone preparations undergo a chemical extraction process to synthesise the final product.

Another falsehood is that bioidentical hormones more closely resemble the hormones in our bodies. The oestrogen, progesterone and testosterone used in bioidenticals are the same as those used in many forms of HRT.

Claim 2: bioidentical hormones are customised to meet women’s individual needs

Bioidentical hormones, which can be ordered over the internet, claim to monitor hormone levels via salivary testing as a way of individualising therapy.

There are two key problems with this approach. First, there is no evidence of a relationship between symptoms and measured salivary hormones, nor between salivary hormone testing and hormone tissue levels.

Second, hormone testing is not a reliable indicator of hormone levels due to irregular fluctuations, particularly around the time of menopause. Therefore to claim dosages are tailored to an individual’s hormonal profile is not based in science.

The only method to gauge effectiveness of hormonal therapy for the relief of symptoms is via patient reports.

Claim 3: bioidentical hormones are safer

Bioidentical hormone manufacturers claim their products are safer, more efficacious and are less likely to cause breast or uterine cancer. There is currently no evidence to support these claims. There is evidence the reverse is true.

Lack of quality controls and variability in the purity, potency and absorption of bioidentical hormones can lead to under or over-dosing. Of particular concern is the under-dosing of progesterone, which protects the uterus from cancer. This is considered the cause of several cases of endometrial cancer.

Conversely, women taking bioidentical hormones have been found to have very high levels of oestrogen.

Bottom line

Menopausal women have been driven towards the false promises of bioidentical hormone therapy and may not be aware of the potential dangers.

Rest assured that conventional, regulator-approved HRT in the lowest effective dose is safe and effective for the short-term relief of menopausal symptoms for women in their 50s.

Authors

1. 

   Rhonda Garad

   PhD student in health literacy at Deakin University

2. 

   Henry Burger

   Emeritus Director at Prince Henry's Institute