Body-Identical vs Bio-Identical

Let’s look at the difference between body-identical and bio-identical hormones.


Body-identical hormones are precise duplicates of estradiol, estriol, estrone, progesterone, DHEA and testosterone as synthesised by the human ovary and adrenal glands. These hormones are safe and regulated. They are available on the NHS.


On the other hand, regulations on bio-identical are not common. They are not available on the NHS. However, they are available in some private clinics. There is a lot of research available and it’s important to know what you are taking.

Most bio-identical hormones are custom made (compounded). This makes it easier to prescribe these hormones in combination doses, and make it more personalised to your needs.


Some hormones found in these bio-identical compounds are not approved for women. For example, a hormone called DHEA (Dehydroepiandrosterone) or prednisolone.

Some “natural” progesterone creams for your skin are available online, but not on the NHS. I do not recommend these. They do not get absorbed into the body. In addition to this, they are not effective as most do not have enough hormones.

What does ‘natural products’ mean?

Many women want to take products that are as “natural” as possible for their menopause.

Many medicines are considered natural because they are derived from plants. However, many are unsafe and some have even been shown to have harmful effects on our bodies. For example, although black cohosh has been shown to give some benefit in treating hot flushes, some types of black cohosh are associated with liver toxicity.

On the other hand, some types of older HRT contain a mixture of different types of oestrogens derived from pregnant mares’ urine. Some would consider this HRT to be natural but it is not body-identical. Why? Because it contains many types of oestrogen that your body does not need. Doctors rarely prescribe this HRT.


Progestogens are synthetic progesterone. There are many different types of progestogens available for women.

Body-identical progestogen

Micronise progesterone (Utrogestan) is the most common type of prescribed progesterone. This is a “body identical” progestogen as it has the same molecular structure as the progesterone made in our bodies. It has fewer side effects than other types of progestogens available. Side effects of progestogens can include bloating, spots and mood swings. The plant chemical used in micronised progesterone is also found in yams.

There is not association with an increased risk of breast cancer for the first five years of taking micronised progesterone. After five years, the risk of breast cancer are still very low. It seems to be lower than the risk for a woman taking the older types of progestogen.


It’s important to pay attention to the type of HRT that you are taking. If you are not certain about something, it is ok to get a second opinion. Check the National Institute for Health and Care Excellence (NICE) for approval of the HRT you are taking.