What is HRT (Hormone Replacement Therapy)?

Published: 18/05/2022

An explanation of what HRT is, how HRT and menopause are related and what women can expect during their HRT treatments.

What is HRT?

This is the third in our series on Menopause. Check out our other articles on HRT to gain a deeper perspective into its role in menopause support:

The Link Between Breast Cancer and HRT

Alternatives to HRT (Hormone Replacement Therapy)

HRT: Hormone Replacement Therapy

Hormone replacement Therapy or HRT is a group of hormonal medicines to treat symptoms of menopause.  The hormones are oestrogen and progestogen and sometimes testosterone.

There are different ways HRT can be taken with different combinations of the hormones, all of which are tailored to suit each individual woman.  For example some medication will contain oestrogen only and others will contain a combination of oestrogen and progestogen.  The Mirena Coil (LNG-IUS) can be used for the progestogen component of HRT, which is ideal if a woman still requires contraception.  Testosterone is usually given separately.  

Oestrogen and HRT

Let’s start with oestrogen - this hormone is the main part of HRT and is given to reduce or stop menopausal symptoms to make you feel better.  It can be given in tablet form, as a topical gel or spray, or as a skin patch.  Usually the oestrogen in the medication is called oestradiol. This closely matches the oestrogen created in your body and works in a similar way, called ‘bioidentical’ or ‘body identical’.  Sometimes the medications contain conjugated oestrogens which is a mix of oestrogens. These don’t match the ones created in your body but still work in a similar way. These are not used as much anymore in the UK.

When you take HRT you will take oestrogen every day.  Quite often a table is tried first but this can depend on individual preference, your own medical history and your family history.  For example if you have had a blood clot or have a family history of blood clots such as DVT (deep vein thrombosis) you will need a patch or a gel as these do not increase the risk of having a blood clot, whilst taking a tablet can increase the risk slightly.

Taking oestrogen on its own can cause the womb lining to thicken and after a period of time could increase the risk of womb cancer. To prevent this progestogens are given alongside.

If you have had a hysterectomy (surgical removal of the womb) you will need oestrogen only HRT.

When using HRT the lowest, effective dose possible is used to alleviate symptoms. The dose is can be steadily increased if little or no benefit is experienced.  It is usually recommended that you take HRT for at least 3 months to gain the maximum benefit. This can be reviewed after the initial 3 months trial period.  Sometimes the route in which HRT is given may be changed, for example from a tablet to a patch due to difficulties in absorption.

Progestogen and HRT

If you have a womb (i.e. have not had a hysterectomy) then you will need to take progestogen alongside oestrogen. Taking oestrogen on its own can cause the womb lining to thicken and after a period of time could increase the risk of womb cancer. To prevent this, progestogens are given alongside. Progesterone is a natural hormone and some HRT contain micronized progesterone which mimics the one our own body makes.

If you are still having periods or it is not 12 months since your last period (perimenopausal) you will be prescribed ‘sequential or cyclical’ HRT. Oestrogen is given for the first 2 weeks followed by a combination of oestrogen and progestogen for the next 2 weeks.  You can expect a monthly withdrawal bleed which usually lasts 3-6 days, either towards the end of the combination of the two hormones or at the start of a new cycle of HRT.  After a few months of taking this combination of HRT you should start to predict when you will have a bleed.  Some unscheduled bleeding can be expected in the first few months of starting this type of HRT.

If you have not a period for over 12 months (post-menopausal) you will be usually be given ‘continuous combined’ HRT.  This is where both oestrogen and progestogens are given together every day.  This type of HRT should not give you a monthly bleed, however it is important to know that you may experience some bleeding within the first 3-6 months of taking this kind of HRT.

Many women choose to have a Mirena coil inserted as their progestogen component of HRT, especially if they still require contraception.  Some women may already have the Mirena the coil, as long as it has not been in place for more than 5 years then oestrogen can be added alongside it.  The Mirena coil must be changed after 5 years if it is being used as part of HRT. 

Testosterone and HRT

Around 100-400mcg of testosterone per day is produced in young women and reduces as we age, usually until over the age of 40.  Testosterone is important for sexual arousal and orgasm so when the levels decrease some women can feel less interested in sex and have difficultly being aroused.  Loss of testosterone can also have an impact on a woman’s energy levels. Some women report having less energy than previously and unmotivated to take part in their usual activities.  

Testosterone is not routinely given as part of HRT. Replacing oestrogen can help with loss of libido and testosterone is never given on its own. It will only be considered when other potential causes of low libido have been excluded and when HRT has not helped. Testosterone is given in a topical gel applied to the skin. It is not licensed for use in women, but can be used off licence in the UK.  Regular blood tests are usually required once established on testosterone and it can take three to six months before you see any benefits.  Unfortunately testosterone does not work for everyone.

Pros and cons of HRT

As with taking any medicines, there are potential risks alongside the benefits of using HRT.  The risks and benefits should always be discussed as well as considering your medical history, to see what is right for you.  Benefits and risks will vary from woman to woman. These are strongly linked to diet, lifestyle, past medical and family history. For most women the short term benefits outweigh the risks of taking HRT. The safety of HRT largely depends on a woman’s age: if HRT is started under the age of 60 in healthy women, then there are no real concerns especially when HRT is started within a few years of menopause.

  • Venous Thrombo-embolism or blood clot (VTE):  There is a small increased risk of having a VTE if taking a tablet but not with a patch/spray or gel HRT (transdermal). If you are at high risk for VTE, including those with Body Mass Index over 30, you should be offered transdermal HRT.

  • Cardiovascular disease:  There is no increased risk when HRT is started under 60. There appears to be a small increased risk of stroke within the first year of taking a tablet but no increased risk with transdermal HRT.  Studies have shown that starting HRT before the age of 60, or within 10 years of the menopause may protect the heart and reduce the risk of heart disease.

  • Diabetes: HRT does not affect risk of developing diabetes. 

  • Breast cancer: HRT does not affect your risk of having breast cancer. Oestrogen only HRT is associated with little or no increased risk of breast cancer. 

HRT with both oestrogen and progestogen is associated with a small increased risk of breast cancer if it is taken for 5 years or more. The risk of breast cancer reduces after stopping HRT.  However, you are at greater risk of breast cancer if you are overweight and drink more than 14 units of alcohol per week than by using HRT. 

  • Osteoporosis:  Using HRT protects the bones and reduces the risk of fractures caused by osteoporosis.  

This is the third in our series on Menopause. Check out our other articles to get a full understanding of what the Menopause means for many women:

What is Menopause Exactly?

Better Understanding Menopause Symptoms in the Workplace

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