What are bioidentical hormones?

Hormone replacement therapy isn’t one thing – its an umbrella term that includes hormones and hormone-like drugs at different doses and different routes of application.

Hormones, or bioidentical hormones such as estradiol and progesterone are hormones that have exactly the same molecular structure as the human body’s own hormones. That means they only bind to the receptors that our own body’s hormones bind to and our body knows exactly how to metabolise them.

Synthetic hormone-like drugs such as conjugated equine oestrogens and synthetic progestogens are not identical in structure to the human body’s own oestrogen and progesterone and they may bind to other receptors causing unwanted effects.

This is a really big deal because it affects our symptoms and risk of diseases. For example:

1) synthetic progestogens don’t only bind to the progesterone receptor but can also bind to glucocorticoid, mineralocorticoid and androgen receptors. This can result in unwanted side effects such as problems with blood sugars, fluid retention, acne and weight gain.

2) Whilst bioidentical progesterone has a calming effects, synthetic progestogens can cause anxiety and irritability.

3) Whilst bio-identical progesterone has been shown to act as a diuretic and lower blood pressure and cholesterol, synthetic progestogens can cause depression, fluid retention and worsen the cholesterol profile.

Large studies such as the E3N cohort study of over 80,000 women have shown that the risk of breast cancer is increased in women taking oestrogen and a synthetic progestogen whereas the risk of breast cancer in women taking bioidentical oestrogen and progesterone was the same as those women not taking HRT. Compared with women who had never used HRT, those taking oestrogen and a synthetic progestogen had 1.69 x increased risk of breast cancer. Compared with women who had never used HRT, those taking bioidentical oestrogen and progesterone had no increased risk of breast cancer. A review in Climacteric states that bioidentical oestrogen plus progesterone does not increase breast cancer risk for up to 5 years of treatment and that there is limited evidence of slightly increased breast cancer risk after 5 years.

We need more studies but as the British Menopause Society states, evidence from large studies suggests that micronised (bioidentical) progesterone is associated with a lower risk of breast cancer compared to that noted with oral progestogens.

You might wonder why synthetic hormone-like drugs were ever made! Its historical. Synthetic hormone like drugs were developed before we had the processes (such as micronisation) to make bioidentical hormones.

But the real question is – why are we still talking about HRT as if its all the same thing? Why not only use hormones that are identical in structure to the body’s own that have clearly defined actions in the human body?

The Differences Between Bioidentical and Synthetic Hormones

In 2002 the Women’s Health Initiative (WHI) study showed that women taking synthetic hormone-like drug had a higher rate of breast cancer , heart attack and strokes than women taking a placebo. The results shocked the public and doctors – prior to that HRT had been considered the elixir of youth! Hormones are highest when we’re young and as they decline we see a number of diseases of ageing. Hormones are key for the heart, the brain, the bones, not to mention hair,

skin, muscle strength bladder function, thermoregulation, metabolism and just about everything else you can think of. Something didn’t add up. The WHI had a profound effect on the prescribing of HRT and on the lives of millions of menopausal women over the last decade who were left feeling at best confused and at worst terrified by the headlines.

In the 10 years following, there has been lots of debate about just how worried women should be. The increase in heart attacks and strokes seen in the WHI is no longer a worry and this is reflected in the latest guidelines – it is now widely accepted that this was seen in the trial because

overweight women over a decade older than the average age of menopause were given a relative overdosage of synthetic hormone-like drugs which likely contributed to the problems.

Oestradiol has been shown time and again to be heart protective.

But what about the breast cancer issue? This is what most women worry about and rightly so. So how worried should women be? Some say the headlines were reported in alarmist

ways, with risks reported as percentages rather than absolute numbers, e.g. 26 per cent increase in risk of breast cancer rather than 1 extra case per 1000 women per year. Then

more recently some other headlines stated that the risk of breast cancer hadn’t been underestimated. Either way, it remains true that HRT containing synthetic progestogens DOES increase the risk of breast cancer.

Then some researchers quite rightly asked one very interesting question: how would the results have differed if women had only been given oestrogen and progesterone that was bioidentical – ie identical in structure to their body’s own?

In 2008 the French E3N cohort study looked at 80,377 postmenopausal women to see how the risk of breast cancer varied with different types of hormone replacement.

The E3N cohort study reported on the association between various other HRTs and breast cancer risk in 80,377 postmenopausal women after up to 12 years of follow-up.

Compared with women who had never used HRT, those taking oestrogen and a synthetic progestagen had 1.69 x increased risk of breast cancer.

Compared with women who had never used HRT, those taking bioidentical oestrogen and progesterone had no increased risk of breast cancer. A review in Climacteric states that bioidentical oestrogen plus progesterone does not increase breast cancer risk for up to 5 years of treatment and that there is limited evidence of slightly increased breast cancer risk after 5 years.

Here’s a bit more about the differences between bioidentical hormones and synthetic hormone like drugs:

Bioidentical progesterone versus synthetic progestogens:

Heart: Bioidentical progesterone reduces plaque in the arteries, relaxes smooth muscle in arteries and has a neutral effect on cholesterol and blood sugars.

Synthetic progestogen medroxyprogesterone acetate increases plaque, has a negative impact on blood sugars and predisposes to diabetes and negates the beneficial effects of oestrogen on the arteries.

Liver: Synthetic progestogens have been shown to have undesirable effects on liver metabolism.

Blood clots: Synthetic progestogens (the norpregnane group) were associated with a

1.8x increased risk of clots whereas no increased risk of clots was found with bioidentical progesterone.

Bioidentical oestrogen versus conjugated equine oestrogens:

Heart: Bio-identical oestrogen has been shown to improve insulin sensitivity, reduce arterial plaques and heart disease and blood pressure. Synthetic oestrogens have been shown to have a negative impact on cholesterol.

Liver: Synthetic oestrogens have been shown to increase gallstones and cholestatic jaundice as well as elevate liver enzymes.

We will always want and need more studies are needed but the message is clear – hormone replacement therapy isn’t all the same thing! Where possible choose bioidentical oestrogen and bioidentical progesterone.

Pros and Cons of Bioidentical hormone Replacement Therapy

When it comes to talking bioidentical hormones there are two options.

The first option is to see your GP and request to use one of the standardised bioidentical hormone products that are available on the NHS for treatment of menopause.

The second option is to see a private bioidentical hormone doctor who does hormone tests for hormonal imbalances at all stages of life and recommends compounded bioidentical hormones specifically for your needs.

Bio (body) identical standardised products available on the NHS

They are made by large pharmaceutical companies which means they are made in bulk and tightly regulated by the MHRA and GPhC in the UK

They are standardised, licensed products.

They usually have a shelf -life of a couple of years

The specific formulation is licensed. For a product to be licensed it must be licensed at one dose for one disease eg estradiol 1mg for menopause. These products come in fixed doses which can be made in bulk.

As a result of mass production the cost of body identical hormones are relatively inexpensive.

The approach: Mainstream medicine uses hormone replacement therapy specifically for treatment of menopause. Other hormonal imbalances are not usually being tested for or treated. Typically, no hormone tests are done. A standardised dose is commenced for treatment of menopause.

Best for: standard uncomplicated menopause treatment.

Cons:

It’s a “one dose fits all” approach to menopause that doesn’t consider the subtleties of perimenopause or hormonal imbalance at any other time of life

There are very limited options for patients who have side effects and require more precise dosing and delivery methods.

There are issues with supplies: you might find a product that suits you only to no longer be able to access it.

Bioidentical compounded products available privately:

They are unlicensed products. They are specific to each patient so that sensitivities and intolerances are taken into consideration.

They are made by small compounding pharmacies, made up for the individual and tightly regulated by the GPhC in the UK.

They usually have a shorter shelf life of up to 6 months .

The specific formulation is unlicensed as it can vary due to the bespoke nature of the product.

As a result of small batch production and the bespoke nature of bioidentical hormones, these are more expensive to produce.

The approach: The approach is to test hormone levels and just give the patient what they need. This is not limited to menopause – hormonal imbalances at all ages are being tested for and treated. After testing, the patient is given an individualised prescription. Further down the line they will have repeat tests and prescription adjusted as necessary.

Best for: treating hormonal imbalances at all ages; where there is a need for more precise menopause treatment; when other health issues such as multiple chemical sensitivities or gut issues are present; those on a holistic health journey who are looking to understand what is going on in their bodies and make lifestyle adjustments.

Cons

Compounded bioidentical hormones are not routinely recommended because they are not licensed. However compounded pharmacies are regulated by the GPhC. For a medication to be licensed it must be licensed at a specific dose and route for a specific condition. Compounded bioidentical hormones which are made up in individualised doses are therefore unlicensed. However in the Uk there are many circumstances in which compounded medicines are used. The General Pharmaceutical Council issues guidance on compounding and its practiced in many NHS hospitals to meet patients’ unmet needs. Compounding is a regulated activity and compounding pharmacies in the UK are tightly regulated by the General Pharmaceutical Council.

It’s expensive because it requires ongoing monitoring with private appointments and tests