Body identical hormones

Body identical HRT has the same structure as the hormones your body produces and is the gold standard of HRT

Body identical HRT is naturally derived and the safest type of hormone replacement therapy
It comes in many different formats, which gives women choice
Advice on deciding what’s right for you

There are so many different types of HRT available, it can be confusing to know which is the most effective and has the least risks associated with it. You may have heard the terms such as ‘body identical HRT’, ‘bioidentical’ or ‘compounded’ HRT. But what do they all mean? And more importantly, which one should you take?

What are body identical hormones?

The safest and most regulated type of HRT is body identical HRT. It is thoroughly tested and researched, recommended by the National Institute of Health and Care Excellence (NICE) guidelines [1], and prescribed by the NHS.

This includes oestradiol you take through your skin in a patch, gel or spray, micronised progesterone, mostly commonly known as Utrogestan in the UK, and testosterone.

Body identical HRT is derived from the yam plant and soy and has the same molecular structure as the hormones your body naturally produces.

Body identical oestrogen treatments

The oestrogen in most body identical forms of HRT is called 17 beta-oestradiol. Oestradiol via a patch, gel or spray is best as this is absorbed directly through the skin and has less side effects and no risk of blood clot (oestrogen tablets have a small risk of clot).

Some types of older HRT contain a mixture of different types of oestrogens and could not be described as body identical, but these are less likely to be prescribed by doctors these days.

RELATED: Oestrogen matters

Body identical progesterone treatments

If you still have a womb, it is important that a progesterone or progestogen (a synthetic version of progesterone) is prescribed alongside the oestrogen for your HRT, in order to keep your womb lining thin and healthy.

The body identical type of progesterone is called micronised progesterone and this mirrors your body’s own natural progesterone. In the UK, this comes in a capsule that you swallow (or insert vaginally) and is branded as Utrogestan. Natural progesterone can also be prescribed as a vaginal or rectal pessary. These types have fewer side effects than other types of synthetic progestogens and are not associated with any risks to your health.

Many women opt to have a Mirena coil to receive progestogen. While this is not classed as body identical, it is a very safe and effective type of progestogen and is shown to have the least side effects or risk compared to other types. Natural progesterone can be used with the Mirena coil.

Oestrogen and progesterone combined

Patches are available that contain oestradiol and progestogen but the progestogen part is not body identical.

There is now a tablet available that contains both body identical oestrogen (1mg oestradiol) and body identical progesterone (100mg). This comes in a softgel capsule and is swallowed daily. It is branded in the UK as Bijuve and in the US as Bijuva. This is an option for some women who are keen to take tablets.

Testosterone

Testosterone comes in gels and a cream. They are body identical and are derived from the yam plant or soy.

What are ‘compounded bioidentical’ types of HRT?

Some private clinics use ‘compounded bioidentical’ hormones.

Compounded bioidentical hormones are not regulated in the same way as prescription medication. The hormones are custom made in order to prescribe them in combination doses or preparations that are not routinely available.

Know your types of HRT

It is important to research any menopause treatments before you commit to taking anything. There is no evidence that compounded bioidentical hormones have fewer side effects or are more effective than body identical HRT, and these treatments have not passed the same rigorous checks that body identical types of HRT have.

Unfortunately, many people do not realise this and spend large sums of money on treatments that can potentially cause several unwanted side effects, little improvement of their symptoms and no proven protection for their future health.

It is very important that you are given the safest type of HRT – body identical HRT – and in the right preparation and strength for your individual needs. You doctor or nurse should fully discuss the benefits and any risks of your HRT for you as an individual.

RELATED: HRT doses explained

Resources

Newson L.R., Lass A. (2018), ‘Effectiveness of transdermal oestradiol and natural micronised progesterone for menopausal symptoms’, Br J Gen Pract, 68(675) pp499-500. doi: 10.3399/bjgp18X699353

References

1. NICE [NG23] (2024), ‘Menopause: identification and management’