Oestrogen Hormone Therapy

What is oestrogen?

Oestrogen is a hormone produced by the ovaries. It has a wide range of important effects including:

Regulating our periods
Maintaining the thickness of the vaginal wall and promotes lubrication.
Protecting the bones and joints
Helps to keep skin and hair healthy
Impacts brain function, including increasing the happy hormone serotonin.

During perimenopause, the level of oestrogen in our body can unpredictably swing from high to low. These swings can cause large changes to our periods, mood, joints, hair and skin.

Our oestrogen levels will eventually fall as we approach menopause and move into post menopause life. This decline can also introduce your menopausal symptoms.

Who needs to take oestrogen as part of hormone replacement therapy (HRT)?

Everyone!!
Oestrogen replacement is central to any HRT. This is simply because oestrogen is the main driver of menopausal symptoms.

There are a few different types of oestrogen that can be in hormone therapies. The type of oestrogen with the lowest risk is something called 17 beta-oestradiol. This is the 'body identical' form of oestrogen - meaning it has exactly the same chemical structure as the hormones your body natually produces.

There are older forms of hormone therapy that contain different types of oestrogens. One of these is premarin - quite well know for being from the urine of pregnant horses. Although some suggest this is natural - it is not body identical and a little outdated. We wouldn't expect doctors today to prescribe this form of oestrogen hormone therapy.

What are the different types of oestrogen HRT?

Body identical oestrogen HRT can come as tablets, patches or gels. Each form has their advantages and disadvantages - ultimately the type for you will depend on your own lifestyle and preferences. A good HRT consultation will take into account your lifestyle, and should explain the risks and benefits of each option.

Oestrogen HRT tablets

Advantages:

If you already take medications or supplements each day, it can be easy to remember to take a daily pill.
Easy to know when you are running out of tablets.
If you are getting HRT privately tablets are often the most cost effective form.

Disadvantages:

Higher risk of blood clots than transdermal forms of HRT (gels and patches). This size of this risk differs depending on the type of oestrogen in the tablet. Body identical oestrogen tablets have the smallest increased risk. Non-body identical forms have a larger risk.
Some women find it difficult to remember to take tablets everyday, especially if this is not part of their normal routine.
Because tablets are absorbed through the digestive system, it's more likely that digestive problems might occur.
Women with migraines should not take tablets. This is because there's a small increased risk of stroke with this form of HRT. Women who suffer with migraines are already at an increased risk of stroke, so taking oestrogen as a patch or gel is better for them.
Tablet oestrogen may lower libido. Taking oestrogen tablets can increase levels of Sex Hormone Binding Globulin (SHBG). This hormone binds to the testosterone in your blood - lowering libido. Oestrogen as a patch or gel does not increase SHBG, so this form of HRT does not have this effect.
Tablets are a fixed daily dose of oestrogen. With gels and patches, the dose can be adjusted more easily. Finding the right dose for your body may take some adjustments, and this can be easier with gels and patches.

Transdermal Oestrogen HRT as patches and gels

Advantages:

Lower risk of blood clots.
Lower risk of digestive issues.
Lower risk of decreased libido.
Easier to tailor the dosing as you can change patches more or less frequently, and apply more of less of a gel sachet.
Some women find patches very convenient as they stay on the skin for days, meaning you do not have to remember something daily for HRT.

Disadvantages of patches:

Some women who have sensitive skin may react to the adhesive of patches.
Patches are in shorter supply than other forms of HRT at the moment (spring 2020). Shortages are expected to improve over the coming months.
If you are getting your HRT prescription privately patches are often the most expensive.

Disadvantages of gel:

Most women absorb the gel very easily, but a small number of women do not. No other creams should be applied for an hour after applying the gel to support absorbption.
In general, the gel is applied daily which can be harder to remember.
If you are getting your HRT prescription privately gel more cost effective than patches, but still more than tablets.

What are the risks attached to oestrogen HRT?

As outlined above, the risks depend on the form of HRT you take. Often women are worried about breast cancer with HRT. This is because of older evidence suggesting HRT made your chances of developing breast cancer much greater. The evidence has really moved on since this famous study.

With breast cancer risk, the important things to remember are:

Women under 51 years old do not have an increased risk of getting breast cancer when using HRT, regardless of the length of time they take it for. This is important. Taking HRT when you are younger can reduce your long term risks for osteoporosis, dementia and coronary heart disease.
Women without a womb, taking only oestrogen, do not have an increased risk of breast cancer.
The small increased risk of breast cancer for older women comes from the progesterone part of combined HRT. Body identical progesterone (micronised progesterone) has lower risks. The increased risk is very small for the first 5 years of taking HRT, and increases slightly after having taken HRT for 5 years. To put the risk into perspective, it is less than being overweight, obese or drinking a couple of glasses of wine a night.
It's also important to note that if you do get breast cancer (which 1 in 8 women do, regardless of HRT), the chances of survival are not reduced if you take HRT. In fact, the survival chances may be better if you take HRT, but more evidence is needed to confirm this.

Other risks depend on the form and type of HRT you take. Body identical oestrogen has much lower risks than older forms of oestrogn. As outlined above tablets have a higher risk of clotting than patches or gels.

Do I need to know anything else about HRT?

There are many different types of HRT you can try. If one type doesn't work for you, there's many others you can try before giving up. This is why it's important to track your symptoms as you start to take HRT, and throughout your menopause journey.

If you need combined HRT it can be useful to have the oestrogen and progesterone prescribed separately. This allows the dose of oestrogen to be tweaked without changing the progesterone. To learn more about combined HRT, and the different methods of administration, take a look at our Hormone Replacement Therapy (HRT) - explained article.

References:

Main, C., Sanchez, G., Knight, B., Sanchez-Gomez, L., Roqué M Figuls, M. and Cosp, B., 2013. Hormone Therapy for preventing cardiovascular disease in post-menopausal women. Cochrane Library, [online] (2).
Available at: https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD002229.pub3/full.
Hillard, T., Abernathy, K., Hamoda, H., Shaw, I., Everett, M., Ayres, J. and Currie, H., 2017. Management Of The Menopause. 6th ed. British Menopause Society.
nhs.uk. n.d. Hormone Replacement Therapy (HRT). [online]
Available at: https://www.nhs.uk/conditions/hormone-replacement-therapy-hrt/. [Accessed 16 March 2020]
Panay, N., Briggs, P. and Kovacs, G., 2015. Managing The Menopause. Cambridge University Press.

5 Asi, N., Mohammed, K., Haydour, Q., Gionfriddo, M., Vargas, O., Prokop, L., Faubion, S. and Murad, M., 2016. Progesterone vs. synthetic progestins and the risk of breast cancer: a systematic review and meta-analysis. Systematic Reviews, [online] 5(1).
Available at: https://systematicreviewsjournal.biomedcentral.com/articles/10.1186/s13643-016-0294-5.