Replacing the hormone oestrogen is a crucial part of all hormone replacement therapy (HRT). Here we explain why oestrogen is so important; who it's suitable for; the different forms of oestrogen HRT; and the risks associated with each form.
Oestrogen is a hormone produced by the ovaries. It has a wide range of important effects including:
During perimenopause level of oestrogen in our body can swing from high to low. These swings can cause large changes to our periods, mood, joints, hair and skin - and create those pesky perimenopause symptoms.
Our oestrogen levels reduce as we approach menopause and move into post menopause life. This decline can also introduce symptoms.
Everyone. Oestrogen replacement is central to any HRT because oestrogen is the main driver of 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 in your body.
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 Although some suggest this is natural - it is not body identical and a little outdated.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.
Body identical oestrogen HRT can come as tablets, patches or gels. Each form has some advantages and disadvantages - and 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.
Disadvantages of patches:
Disadvantages of gel:
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 increased slightly after 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) that 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.
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.
1 Gabriel Sanchez R, Sanchez Gomez LM, Carmona L, Roqué i Figuls M, Bonfill Cosp X. Hormone replacement therapy for preventing cardiovascular disease in post‐menopausal women. Cochrane Database of Systematic Reviews 2005, Issue 2. Art. No.: CD002229. DOI: 10.1002/14651858.CD002229.pub2.
2 Hillard T., et al. (2017). Management of the menopause. 6th edn. British Menopause Society. UK.
3 National Health Services Website (2018). *Types - Hormone Replacement Therapy - * Retrieved 16 March 2020 from [https://www.nhs.uk/conditions/hormone-replacement-therapy-hrt/types/].
4 Panay, N., Briggs, P., & Kovacs, G. (Eds.). (2015). Managing the Menopause: 21st Century Solutions. Cambridge: Cambridge University Press.
5 A, Noor et al. (2016). “Progesterone vs. synthetic progestins and the risk of breast cancer: a systematic review and meta-analysis.” Systematic reviews vol. 5,1 121. 26 Jul. 2016, doi:10.1186/s13643-016-0294-5